diff --git a/react/features/app/components/App.web.js b/react/features/app/components/App.web.tsx
similarity index 96%
rename from react/features/app/components/App.web.js
rename to react/features/app/components/App.web.tsx
index ba03db6faa..ed7ec0e1ec 100644
--- a/react/features/app/components/App.web.js
+++ b/react/features/app/components/App.web.tsx
@@ -43,7 +43,7 @@ export class App extends AbstractApp {
      *
      * @override
      */
-    _createMainElement(component, props) {
+    _createMainElement(component: React.ComponentType, props: any) {
         return (
             <JitsiThemeProvider>
                 <AtlasKitThemeProvider mode = 'dark'>
diff --git a/react/features/app/getRouteToRender.native.js b/react/features/app/getRouteToRender.native.ts
similarity index 78%
rename from react/features/app/getRouteToRender.native.js
rename to react/features/app/getRouteToRender.native.ts
index ef929dd4de..3e42f41b4e 100644
--- a/react/features/app/getRouteToRender.native.js
+++ b/react/features/app/getRouteToRender.native.ts
@@ -10,8 +10,9 @@ const route = {
  * Determines which route is to be rendered in order to depict a specific Redux
  * store.
  *
+ * @param {any} _stateful - Used on web.
  * @returns {Promise<Object>}
  */
-export function _getRouteToRender() {
+export function _getRouteToRender(_stateful: any) {
     return Promise.resolve(route);
 }
diff --git a/react/features/app/getRouteToRender.web.js b/react/features/app/getRouteToRender.web.ts
similarity index 82%
rename from react/features/app/getRouteToRender.web.js
rename to react/features/app/getRouteToRender.web.ts
index 85d4089c2d..932ac1ab44 100644
--- a/react/features/app/getRouteToRender.web.js
+++ b/react/features/app/getRouteToRender.web.ts
@@ -1,16 +1,21 @@
-
+// @ts-expect-error
 import { generateRoomWithoutSeparator } from '@jitsi/js-utils/random';
 
+import { IStateful } from '../base/app/types';
 import { isRoomValid } from '../base/conference/functions';
 import { isSupportedBrowser } from '../base/environment/environment';
 import { toState } from '../base/redux/functions';
+// eslint-disable-next-line lines-around-comment
+// @ts-ignore
 import Conference from '../conference/components/web/Conference';
 import { getDeepLinkingPage } from '../deep-linking/functions';
 import UnsupportedDesktopBrowser from '../unsupported-browser/components/UnsupportedDesktopBrowser';
-import BlankPage from '../welcome/components/BlankPage';
-import WelcomePage from '../welcome/components/WelcomePage';
+import BlankPage from '../welcome/components/BlankPage.web';
+import WelcomePage from '../welcome/components/WelcomePage.web';
 import { getCustomLandingPageURL, isWelcomePageEnabled } from '../welcome/functions';
 
+import { IReduxState } from './types';
+
 /**
  * Determines which route is to be rendered in order to depict a specific Redux
  * store.
@@ -19,7 +24,7 @@ import { getCustomLandingPageURL, isWelcomePageEnabled } from '../welcome/functi
  * {@code getState} function.
  * @returns {Promise<Object>}
  */
-export function _getRouteToRender(stateful) {
+export function _getRouteToRender(stateful: IStateful) {
     const state = toState(stateful);
 
     return _getWebConferenceRoute(state) || _getWebWelcomePageRoute(state);
@@ -32,7 +37,7 @@ export function _getRouteToRender(stateful) {
  * @param {Object} state - The redux state.
  * @returns {Promise|undefined}
  */
-function _getWebConferenceRoute(state) {
+function _getWebConferenceRoute(state: IReduxState) {
     if (!isRoomValid(state['features/base/conference'].room)) {
         return;
     }
@@ -45,8 +50,8 @@ function _getWebConferenceRoute(state) {
     // room into account.
     const { locationURL } = state['features/base/connection'];
 
-    if (window.location.href !== locationURL.href) {
-        route.href = locationURL.href;
+    if (window.location.href !== locationURL?.href) {
+        route.href = locationURL?.href;
 
         return Promise.resolve(route);
     }
@@ -71,7 +76,7 @@ function _getWebConferenceRoute(state) {
  * @param {Object} state - The redux state.
  * @returns {Promise<Object>}
  */
-function _getWebWelcomePageRoute(state) {
+function _getWebWelcomePageRoute(state: IReduxState) {
     const route = _getEmptyRoute();
 
     if (isWelcomePageEnabled(state)) {
@@ -102,7 +107,10 @@ function _getWebWelcomePageRoute(state) {
  *
  * @returns {Object}
  */
-function _getEmptyRoute() {
+function _getEmptyRoute(): {
+    component: React.ReactNode;
+    href?: string;
+    } {
     return {
         component: BlankPage,
         href: undefined
diff --git a/react/features/app/middleware.js b/react/features/app/middleware.ts
similarity index 89%
rename from react/features/app/middleware.js
rename to react/features/app/middleware.ts
index 5d1ae78ad0..96dd8715ad 100644
--- a/react/features/app/middleware.js
+++ b/react/features/app/middleware.ts
@@ -1,4 +1,4 @@
-// @flow
+import { AnyAction } from 'redux';
 
 import { createConnectionEvent } from '../analytics/AnalyticsEvents';
 import { sendAnalytics } from '../analytics/functions';
@@ -10,6 +10,7 @@ import { inIframe } from '../base/util/iframeUtils';
 
 import { reloadNow } from './actions';
 import { _getRouteToRender } from './getRouteToRender';
+import { IStore } from './types';
 
 MiddlewareRegistry.register(store => next => action => {
     switch (action.type) {
@@ -39,7 +40,7 @@ MiddlewareRegistry.register(store => next => action => {
  * @returns {Object} The new state that is the result of the reduction of the
  * specified {@code action}.
  */
-function _connectionEstablished(store, next, action) {
+function _connectionEstablished(store: IStore, next: Function, action: AnyAction) {
     const result = next(action);
 
     // In the Web app we explicitly do not want to display the hash and
@@ -47,6 +48,7 @@ function _connectionEstablished(store, next, action) {
     // importantly, its params are used not only in jitsi-meet but also in
     // lib-jitsi-meet. Consequently, the time to remove the params is
     // determined by when no one needs them anymore.
+    // @ts-ignore
     const { history, location } = window;
 
     if (inIframe()) {
@@ -57,12 +59,14 @@ function _connectionEstablished(store, next, action) {
             && location
             && history.length
             && typeof history.replaceState === 'function') {
+        // @ts-ignore
         const replacement = getURLWithoutParams(location);
 
+        // @ts-ignore
         if (location !== replacement) {
             history.replaceState(
                 history.state,
-                (document && document.title) || '',
+                document?.title || '',
                 replacement);
         }
     }
@@ -81,7 +85,7 @@ function _connectionEstablished(store, next, action) {
  * @returns {Object}
  * @private
  */
-function _connectionFailed({ dispatch, getState }, next, action) {
+function _connectionFailed({ dispatch, getState }: IStore, next: Function, action: AnyAction) {
     // In the case of a split-brain error, reload early and prevent further
     // handling of the action.
     if (_isMaybeSplitBrainError(getState, action)) {
@@ -104,7 +108,7 @@ function _connectionFailed({ dispatch, getState }, next, action) {
  * @private
  * @returns {boolean}
  */
-function _isMaybeSplitBrainError(getState, action) {
+function _isMaybeSplitBrainError(getState: IStore['getState'], action: AnyAction) {
     const { error } = action;
     const isShardChangedError = error
         && error.message === 'item-not-found'
@@ -116,7 +120,7 @@ function _isMaybeSplitBrainError(getState, action) {
         const { timeEstablished } = state['features/base/connection'];
         const { _immediateReloadThreshold } = state['features/base/config'];
 
-        const timeSinceConnectionEstablished = timeEstablished && Date.now() - timeEstablished;
+        const timeSinceConnectionEstablished = Number(timeEstablished && Date.now() - timeEstablished);
         const reloadThreshold = typeof _immediateReloadThreshold === 'number' ? _immediateReloadThreshold : 1500;
 
         const isWithinSplitBrainThreshold = !timeEstablished || timeSinceConnectionEstablished <= reloadThreshold;
@@ -142,7 +146,7 @@ function _isMaybeSplitBrainError(getState, action) {
  * @private
  * @returns {void}
  */
-function _navigate({ getState }) {
+function _navigate({ getState }: IStore) {
     const state = getState();
     const { app } = state['features/base/app'];
 
@@ -163,7 +167,7 @@ function _navigate({ getState }) {
  * @returns {Object} The new state that is the result of the reduction of the
  * specified {@code action}.
  */
-function _setRoom(store, next, action) {
+function _setRoom(store: IStore, next: Function, action: AnyAction) {
     const result = next(action);
 
     _navigate(store);
diff --git a/react/features/base/app/components/BaseApp.tsx b/react/features/base/app/components/BaseApp.tsx
index faf7a0cfbe..35b2c0145c 100644
--- a/react/features/base/app/components/BaseApp.tsx
+++ b/react/features/base/app/components/BaseApp.tsx
@@ -186,7 +186,7 @@ export default class BaseApp<P> extends Component<P, IState> {
      * @abstract
      * @protected
      */
-    _createExtraElement() {
+    _createExtraElement(): React.ReactElement | null {
         return null;
     }
 
@@ -280,5 +280,7 @@ export default class BaseApp<P> extends Component<P, IState> {
      *
      * @returns {React$Element}
      */
-    _renderDialogContainer: () => React.ReactElement;
+    _renderDialogContainer(): React.ReactElement | null {
+        return null;
+    }
 }
diff --git a/react/features/base/config/configType.ts b/react/features/base/config/configType.ts
index 4a20a9ea0a..fbada63788 100644
--- a/react/features/base/config/configType.ts
+++ b/react/features/base/config/configType.ts
@@ -112,8 +112,8 @@ export interface IDeeplinkingMobileConfig extends IDeeplinkingPlatformConfig {
 export interface IDeeplinkingConfig {
     android?: IDeeplinkingMobileConfig;
     desktop?: IDeeplinkingPlatformConfig;
-    disabled: boolean;
-    hideLogo: boolean;
+    disabled?: boolean;
+    hideLogo?: boolean;
     ios?: IDeeplinkingMobileConfig;
 }
 
@@ -127,7 +127,8 @@ export interface INoiseSuppressionConfig {
 
 export interface IConfig {
     _desktopSharingSourceDevice?: string;
-    _screenshotHistoryRegionUrl?: string;
+    _immediateReloadThreshold?: string;
+    _screenshotHistoryRegionUrl?: number;
     analytics?: {
         amplitudeAPPKey?: string;
         blackListedEvents?: string[];
diff --git a/react/features/base/label/components/web/ExpandedLabel.js b/react/features/base/label/components/web/ExpandedLabel.ts
similarity index 100%
rename from react/features/base/label/components/web/ExpandedLabel.js
rename to react/features/base/label/components/web/ExpandedLabel.ts
diff --git a/react/features/base/popover/components/Popover.native.js b/react/features/base/popover/components/Popover.native.ts
similarity index 100%
rename from react/features/base/popover/components/Popover.native.js
rename to react/features/base/popover/components/Popover.native.ts
diff --git a/react/features/base/premeeting/components/web/Preview.js b/react/features/base/premeeting/components/web/Preview.tsx
similarity index 73%
rename from react/features/base/premeeting/components/web/Preview.js
rename to react/features/base/premeeting/components/web/Preview.tsx
index cbe58101d4..6491134601 100644
--- a/react/features/base/premeeting/components/web/Preview.js
+++ b/react/features/base/premeeting/components/web/Preview.tsx
@@ -1,51 +1,48 @@
-// @flow
-
 import React, { useEffect } from 'react';
 import { connect } from 'react-redux';
 
-import { getDisplayName } from '../../../../base/settings/functions.web';
+import { IReduxState } from '../../../../app/types';
 import Avatar from '../../../avatar/components/Avatar';
 import Video from '../../../media/components/web/Video';
 import { getLocalParticipant } from '../../../participants/functions';
+import { getDisplayName } from '../../../settings/functions.web';
 import { getLocalVideoTrack } from '../../../tracks/functions.web';
 
-declare var APP: Object;
-
-export type Props = {
+export interface IProps {
 
     /**
      * Local participant id.
      */
-    _participantId: string,
+    _participantId: string;
 
     /**
      * Flag controlling whether the video should be flipped or not.
      */
-    flipVideo: boolean,
+    flipVideo: boolean;
 
     /**
      * The name of the user that is about to join.
      */
-    name: string,
+    name: string;
 
     /**
      * Flag signaling the visibility of camera preview.
      */
-    videoMuted: boolean,
+    videoMuted: boolean;
 
     /**
      * The JitsiLocalTrack to display.
      */
-    videoTrack: ?Object,
-};
+    videoTrack?: Object;
+}
 
 /**
  * Component showing the video preview and device status.
  *
- * @param {Props} props - The props of the component.
+ * @param {IProps} props - The props of the component.
  * @returns {ReactElement}
  */
-function Preview(props: Props) {
+function Preview(props: IProps) {
     const { _participantId, flipVideo, name, videoMuted, videoTrack } = props;
     const className = flipVideo ? 'flipVideoX' : '';
 
@@ -83,19 +80,19 @@ function Preview(props: Props) {
  * Maps part of the Redux state to the props of this component.
  *
  * @param {Object} state - The Redux state.
- * @param {Props} ownProps - The own props of the component.
- * @returns {Props}
+ * @param {IProps} ownProps - The own props of the component.
+ * @returns {IProps}
  */
-function _mapStateToProps(state, ownProps) {
+function _mapStateToProps(state: IReduxState, ownProps: any) {
     const name = getDisplayName(state);
-    const { id: _participantId } = getLocalParticipant(state);
+    const { id: _participantId } = getLocalParticipant(state) ?? {};
 
     return {
-        _participantId,
-        flipVideo: state['features/base/settings'].localFlipX,
+        _participantId: _participantId ?? '',
+        flipVideo: Boolean(state['features/base/settings'].localFlipX),
         name,
         videoMuted: ownProps.videoTrack ? ownProps.videoMuted : state['features/base/media'].video.muted,
-        videoTrack: ownProps.videoTrack || (getLocalVideoTrack(state['features/base/tracks']) || {}).jitsiTrack
+        videoTrack: ownProps.videoTrack || getLocalVideoTrack(state['features/base/tracks'])?.jitsiTrack
     };
 }
 
diff --git a/react/features/base/react/components/web/InlineDialogFailure.js b/react/features/base/react/components/web/InlineDialogFailure.tsx
similarity index 88%
rename from react/features/base/react/components/web/InlineDialogFailure.js
rename to react/features/base/react/components/web/InlineDialogFailure.tsx
index 1e0f14b925..7245ecbf4e 100644
--- a/react/features/base/react/components/web/InlineDialogFailure.js
+++ b/react/features/base/react/components/web/InlineDialogFailure.tsx
@@ -1,38 +1,29 @@
-/* @flow */
-
 import React, { Component } from 'react';
+import { WithTranslation } from 'react-i18next';
 
 import { translate } from '../../../i18n/functions';
 import Button from '../../../ui/components/web/Button';
 
-
-declare var interfaceConfig: Object;
-
 /**
  * The type of the React {@code Component} props of {@link InlineDialogFailure}.
  */
-type Props = {
+interface IProps extends WithTranslation {
 
     /**
      * Allows to retry the call that previously didn't succeed.
      */
-    onRetry: Function,
-
-    /**
-     * Invoked to obtain translated strings.
-     */
-    t: Function,
+    onRetry: Function;
 
     /**
      * Indicates whether the support link should be shown in case of an error.
      */
-     showSupportLink: Boolean,
-};
+    showSupportLink: Boolean;
+}
 
 /**
  * Inline dialog that represents a failure and allows a retry.
  */
-class InlineDialogFailure extends Component<Props> {
+class InlineDialogFailure extends Component<IProps> {
     /**
      * Renders the content of this component.
      *
diff --git a/react/features/base/react/components/web/MeetingsList.js b/react/features/base/react/components/web/MeetingsList.tsx
similarity index 87%
rename from react/features/base/react/components/web/MeetingsList.js
rename to react/features/base/react/components/web/MeetingsList.tsx
index 6335209a41..5100fcde88 100644
--- a/react/features/base/react/components/web/MeetingsList.js
+++ b/react/features/base/react/components/web/MeetingsList.tsx
@@ -1,6 +1,5 @@
-// @flow
-
 import React, { Component } from 'react';
+import { WithTranslation } from 'react-i18next';
 
 import { getLocalizedDateFormatter, getLocalizedDurationFormatter } from '../../../i18n/dateUtil';
 import { translate } from '../../../i18n/functions';
@@ -10,43 +9,47 @@ import { IconTrash } from '../../../icons/svg';
 import Container from './Container';
 import Text from './Text';
 
-type Props = {
+interface IMeeting {
+    date: Date;
+    duration?: number;
+    elementAfter?: React.ReactElement;
+    time: Date[];
+    title: string;
+    url: string;
+}
+
+interface IProps extends WithTranslation {
 
     /**
      * Indicates if the list is disabled or not.
      */
-    disabled: boolean,
+    disabled: boolean;
 
     /**
      * Indicates if the URL should be hidden or not.
      */
-    hideURL: boolean,
-
-    /**
-     * Function to be invoked when an item is pressed. The item's URL is passed.
-     */
-    onPress: Function,
+    hideURL?: boolean;
 
     /**
      * Rendered when the list is empty. Should be a rendered element.
      */
-    listEmptyComponent: Object,
+    listEmptyComponent: React.ReactNode;
 
     /**
      * An array of meetings.
      */
-    meetings: Array<Object>,
+    meetings: IMeeting[];
 
     /**
      * Handler for deleting an item.
      */
-    onItemDelete?: Function,
+    onItemDelete?: Function;
 
     /**
-     * Invoked to obtain translated strings.
+     * Function to be invoked when an item is pressed. The item's URL is passed.
      */
-    t: Function
-};
+    onPress: Function;
+}
 
 /**
  * Generates a date string for a given date.
@@ -55,7 +58,7 @@ type Props = {
  * @private
  * @returns {string}
  */
-function _toDateString(date) {
+function _toDateString(date: Date) {
     return getLocalizedDateFormatter(date).format('ll');
 }
 
@@ -67,7 +70,7 @@ function _toDateString(date) {
  * @private
  * @returns {string}
  */
-function _toTimeString(times) {
+function _toTimeString(times: Date[]) {
     if (times && times.length > 0) {
         return (
             times
@@ -84,13 +87,13 @@ function _toTimeString(times) {
  *
  * @augments Component
  */
-class MeetingsList extends Component<Props> {
+class MeetingsList extends Component<IProps> {
     /**
      * Constructor of the MeetingsList component.
      *
      * @inheritdoc
      */
-    constructor(props: Props) {
+    constructor(props: IProps) {
         super(props);
 
         this._onPress = this._onPress.bind(this);
@@ -123,8 +126,6 @@ class MeetingsList extends Component<Props> {
         return null;
     }
 
-    _onPress: string => Function;
-
     /**
      * Returns a function that is used in the onPress callback of the items.
      *
@@ -132,18 +133,16 @@ class MeetingsList extends Component<Props> {
      * @private
      * @returns {Function}
      */
-    _onPress(url) {
+    _onPress(url: string) {
         const { disabled, onPress } = this.props;
 
         if (!disabled && url && typeof onPress === 'function') {
             return () => onPress(url);
         }
 
-        return null;
+        return undefined;
     }
 
-    _onKeyPress: string => Function;
-
     /**
      * Returns a function that is used in the onPress callback of the items.
      *
@@ -151,22 +150,20 @@ class MeetingsList extends Component<Props> {
      * @private
      * @returns {Function}
      */
-    _onKeyPress(url) {
+    _onKeyPress(url: string) {
         const { disabled, onPress } = this.props;
 
         if (!disabled && url && typeof onPress === 'function') {
-            return e => {
+            return (e: React.KeyboardEvent) => {
                 if (e.key === ' ' || e.key === 'Enter') {
                     onPress(url);
                 }
             };
         }
 
-        return null;
+        return undefined;
     }
 
-    _onDelete: Object => Function;
-
     /**
      * Returns a function that is used on the onDelete callback.
      *
@@ -174,18 +171,16 @@ class MeetingsList extends Component<Props> {
      * @private
      * @returns {Function}
      */
-    _onDelete(item) {
+    _onDelete(item: Object) {
         const { onItemDelete } = this.props;
 
-        return evt => {
+        return (evt: React.MouseEvent) => {
             evt.stopPropagation();
 
-            onItemDelete && onItemDelete(item);
+            onItemDelete?.(item);
         };
     }
 
-    _onDeleteKeyPress: Object => Function;
-
     /**
      * Returns a function that is used on the onDelete keypress callback.
      *
@@ -193,10 +188,10 @@ class MeetingsList extends Component<Props> {
      * @private
      * @returns {Function}
      */
-    _onDeleteKeyPress(item) {
+    _onDeleteKeyPress(item: Object) {
         const { onItemDelete } = this.props;
 
-        return e => {
+        return (e: React.KeyboardEvent) => {
             if (onItemDelete && (e.key === ' ' || e.key === 'Enter')) {
                 e.preventDefault();
                 e.stopPropagation();
@@ -205,8 +200,6 @@ class MeetingsList extends Component<Props> {
         };
     }
 
-    _renderItem: (Object, number) => React$Node;
-
     /**
      * Renders an item for the list.
      *
@@ -214,7 +207,7 @@ class MeetingsList extends Component<Props> {
      * @param {number} index - The index of the item.
      * @returns {Node}
      */
-    _renderItem(meeting, index) {
+    _renderItem(meeting: IMeeting, index: number) {
         const {
             date,
             duration,
diff --git a/react/features/base/react/components/web/NavigateSectionListEmptyComponent.js b/react/features/base/react/components/web/NavigateSectionListEmptyComponent.ts
similarity index 100%
rename from react/features/base/react/components/web/NavigateSectionListEmptyComponent.js
rename to react/features/base/react/components/web/NavigateSectionListEmptyComponent.ts
diff --git a/react/features/base/react/components/web/NavigateSectionListItem.js b/react/features/base/react/components/web/NavigateSectionListItem.tsx
similarity index 94%
rename from react/features/base/react/components/web/NavigateSectionListItem.js
rename to react/features/base/react/components/web/NavigateSectionListItem.tsx
index 2857440ac2..8d46a69f93 100644
--- a/react/features/base/react/components/web/NavigateSectionListItem.js
+++ b/react/features/base/react/components/web/NavigateSectionListItem.tsx
@@ -1,5 +1,3 @@
-// @flow
-
 import React, { Component } from 'react';
 
 import { Item } from '../../types';
@@ -11,18 +9,18 @@ import Text from './Text';
  * The type of the React {@code Component} props of
  * {@link NavigateSectionListItem}.
  */
-type Props = {
-
-    /**
-     * Function to be invoked when an item is pressed. The item's URL is passed.
-     */
-    onPress: ?Function,
+interface IProps {
 
     /**
      * A item containing data to be rendered.
      */
-    item: Item
-};
+    item: Item;
+
+    /**
+     * Function to be invoked when an item is pressed. The item's URL is passed.
+     */
+    onPress?: Function;
+}
 
 /**
  * Implements a React/Web {@link Component} for displaying an item in a
@@ -30,7 +28,7 @@ type Props = {
  *
  * @augments Component
  */
-export default class NavigateSectionListItem<P: Props>
+export default class NavigateSectionListItem<P extends IProps>
     extends Component<P> {
 
     /**
diff --git a/react/features/base/react/components/web/NavigateSectionListSectionHeader.js b/react/features/base/react/components/web/NavigateSectionListSectionHeader.tsx
similarity index 91%
rename from react/features/base/react/components/web/NavigateSectionListSectionHeader.js
rename to react/features/base/react/components/web/NavigateSectionListSectionHeader.tsx
index 0ea11c7097..1cede21bb0 100644
--- a/react/features/base/react/components/web/NavigateSectionListSectionHeader.js
+++ b/react/features/base/react/components/web/NavigateSectionListSectionHeader.tsx
@@ -1,17 +1,15 @@
-// @flow
-
 import React, { Component } from 'react';
 
 import { Section } from '../../types';
 
 import Text from './Text';
 
-type Props = {
+interface IProps {
 
     /**
      * A section containing the data to be rendered.
      */
-    section: Section
+    section: Section;
 }
 
 /**
@@ -20,7 +18,7 @@ type Props = {
  *
  * @augments Component
  */
-export default class NavigateSectionListSectionHeader extends Component<Props> {
+export default class NavigateSectionListSectionHeader extends Component<IProps> {
     /**
      * Renders the content of this component.
      *
diff --git a/react/features/base/react/components/web/SectionList.js b/react/features/base/react/components/web/SectionList.tsx
similarity index 90%
rename from react/features/base/react/components/web/SectionList.js
rename to react/features/base/react/components/web/SectionList.tsx
index 188a35dbce..0ff5c5ce51 100644
--- a/react/features/base/react/components/web/SectionList.js
+++ b/react/features/base/react/components/web/SectionList.tsx
@@ -1,44 +1,42 @@
-// @flow
-
 import React, { Component } from 'react';
 
 import { Section } from '../../types';
 
 import Container from './Container';
 
-type Props = {
+interface IProps {
 
     /**
      * Rendered when the list is empty. Should be a rendered element.
      */
-    ListEmptyComponent: Object,
+    ListEmptyComponent: Object;
 
     /**
      * Used to extract a unique key for a given item at the specified index.
      * Key is used for caching and as the react key to track item re-ordering.
      */
-    keyExtractor: Function,
-
-    /**
-     * Returns a React component that renders each Item in the list.
-     */
-    renderItem: Function,
-
-    /**
-     * Returns a React component that renders the header for every section.
-     */
-    renderSectionHeader: Function,
-
-    /**
-     * An array of sections.
-     */
-    sections: Array<Section>,
+    keyExtractor: Function;
 
     /**
      * Defines what happens when  an item in the section list is clicked.
      */
-    onItemClick: Function
-};
+    onItemClick: Function;
+
+    /**
+     * Returns a React component that renders each Item in the list.
+     */
+    renderItem: Function;
+
+    /**
+     * Returns a React component that renders the header for every section.
+     */
+    renderSectionHeader: Function;
+
+    /**
+     * An array of sections.
+     */
+    sections: Array<Section>;
+}
 
 /**
  * Implements a React/Web {@link Component} for displaying a list with
@@ -47,7 +45,7 @@ type Props = {
  *
  * @augments Component
  */
-export default class SectionList extends Component<Props> {
+export default class SectionList extends Component<IProps> {
     /**
      * Renders the content of this component.
      *
diff --git a/react/features/base/react/components/web/Watermarks.js b/react/features/base/react/components/web/Watermarks.tsx
similarity index 90%
rename from react/features/base/react/components/web/Watermarks.js
rename to react/features/base/react/components/web/Watermarks.tsx
index 7c760ab877..9c9a8c620b 100644
--- a/react/features/base/react/components/web/Watermarks.js
+++ b/react/features/base/react/components/web/Watermarks.tsx
@@ -1,14 +1,11 @@
-/* @flow */
-
 import React, { Component } from 'react';
+import { WithTranslation } from 'react-i18next';
 import { connect } from 'react-redux';
 
+import { IReduxState } from '../../../../app/types';
 import { isVpaasMeeting } from '../../../../jaas/functions';
 import { translate } from '../../../i18n/functions';
 
-
-declare var interfaceConfig: Object;
-
 /**
  * The CSS style of the element with CSS class {@code rightwatermark}.
  *
@@ -21,38 +18,33 @@ const _RIGHT_WATERMARK_STYLE = {
 /**
  * The type of the React {@code Component} props of {@link Watermarks}.
  */
-type Props = {
+interface IProps extends WithTranslation {
 
     /**
      * The link used to navigate to on logo click.
      */
-    _logoLink: string,
+    _logoLink: string;
 
     /**
      * The url for the logo.
      */
-    _logoUrl: string,
+    _logoUrl?: string;
 
     /**
      * If the Jitsi watermark should be displayed or not.
      */
-    _showJitsiWatermark: boolean,
+    _showJitsiWatermark: boolean;
+
+    /**
+     * The default value for the Jitsi logo URL.
+     */
+    defaultJitsiLogoURL?: string;
 
     /**
      * Whether the watermark should have a `top` and `left` value.
      */
     noMargins: boolean;
-
-    /**
-     * The default value for the Jitsi logo URL.
-     */
-    defaultJitsiLogoURL: ?string,
-
-    /**
-     * Invoked to obtain translated strings.
-     */
-    t: Function
-};
+}
 
 /**
  * The type of the React {@code Component} state of {@link Watermarks}.
@@ -62,31 +54,31 @@ type State = {
     /**
      * The url to open when clicking the brand watermark.
      */
-    brandWatermarkLink: string,
+    brandWatermarkLink: string;
 
     /**
      * Whether or not the brand watermark should be displayed.
      */
-    showBrandWatermark: boolean,
+    showBrandWatermark: boolean;
 
     /**
      * Whether or not the show the "powered by Jitsi.org" link.
      */
-    showPoweredBy: boolean
+    showPoweredBy: boolean;
 };
 
 /**
  * A Web Component which renders watermarks such as Jits, brand, powered by,
  * etc.
  */
-class Watermarks extends Component<Props, State> {
+class Watermarks extends Component<IProps, State> {
     /**
      * Initializes a new Watermarks instance.
      *
      * @param {Object} props - The read-only properties with which the new
      * instance is to be initialized.
      */
-    constructor(props: Props) {
+    constructor(props: IProps) {
         super(props);
 
         const showBrandWatermark = interfaceConfig.SHOW_BRAND_WATERMARK;
@@ -179,7 +171,7 @@ class Watermarks extends Component<Props, State> {
             };
 
             reactElement = (<div
-                className = { className }
+                className = { className } // @ts-ignore
                 style = { style } />);
 
             if (_logoLink) {
@@ -227,9 +219,9 @@ class Watermarks extends Component<Props, State> {
  *
  * @param {Object} state - Snapshot of Redux store.
  * @param {Object} ownProps - Component's own props.
- * @returns {Props}
+ * @returns {IProps}
  */
-function _mapStateToProps(state, ownProps) {
+function _mapStateToProps(state: IReduxState, ownProps: any) {
     const {
         customizationReady,
         customizationFailed,
@@ -248,7 +240,7 @@ function _mapStateToProps(state, ownProps) {
         customizationReady && !customizationFailed
         && SHOW_JITSI_WATERMARK)
     || !isValidRoom;
-    let _logoUrl = logoImageUrl;
+    let _logoUrl: string | undefined = logoImageUrl;
     let _logoLink = logoClickUrl;
 
     if (useDynamicBrandingData) {
@@ -272,4 +264,4 @@ function _mapStateToProps(state, ownProps) {
     };
 }
 
-export default connect(_mapStateToProps)(translate(Watermarks));
+export default translate(connect(_mapStateToProps)(Watermarks));
diff --git a/react/features/base/responsive-ui/components/DimensionsDetector.web.js b/react/features/base/responsive-ui/components/DimensionsDetector.web.ts
similarity index 100%
rename from react/features/base/responsive-ui/components/DimensionsDetector.web.js
rename to react/features/base/responsive-ui/components/DimensionsDetector.web.ts
diff --git a/react/features/base/testing/components/TestHint.web.js b/react/features/base/testing/components/TestHint.web.ts
similarity index 100%
rename from react/features/base/testing/components/TestHint.web.js
rename to react/features/base/testing/components/TestHint.web.ts
diff --git a/react/features/base/ui/components/web/DialogContainer.tsx b/react/features/base/ui/components/web/DialogContainer.tsx
index 4cbaa884e0..dd3780ccd9 100644
--- a/react/features/base/ui/components/web/DialogContainer.tsx
+++ b/react/features/base/ui/components/web/DialogContainer.tsx
@@ -2,7 +2,6 @@ import React, { Component, ComponentType } from 'react';
 import { connect } from 'react-redux';
 
 import { IReduxState } from '../../../../app/types';
-import { IReactionEmojiProps } from '../../../../reactions/constants';
 import JitsiPortal from '../../../../toolbox/components/web/JitsiPortal';
 import { showOverflowDrawer } from '../../../../toolbox/functions.web';
 
@@ -25,11 +24,6 @@ interface IProps {
      */
     _overflowDrawer: boolean;
 
-    /**
-     * Array of reactions to be displayed.
-     */
-    _reactionsQueue: Array<IReactionEmojiProps>;
-
     /**
      * True if the UI is in a compact state where we don't show dialogs.
      */
diff --git a/react/features/calendar-sync/components/AddMeetingUrlButton.web.js b/react/features/calendar-sync/components/AddMeetingUrlButton.web.tsx
similarity index 84%
rename from react/features/calendar-sync/components/AddMeetingUrlButton.web.js
rename to react/features/calendar-sync/components/AddMeetingUrlButton.web.tsx
index 3fc6c33159..a15874ed96 100644
--- a/react/features/calendar-sync/components/AddMeetingUrlButton.web.js
+++ b/react/features/calendar-sync/components/AddMeetingUrlButton.web.tsx
@@ -1,55 +1,49 @@
-// @flow
-
 import React, { Component } from 'react';
+import { WithTranslation } from 'react-i18next';
 import { connect } from 'react-redux';
-import type { Dispatch } from 'redux';
 
 import { createCalendarClickedEvent } from '../../analytics/AnalyticsEvents';
 import { sendAnalytics } from '../../analytics/functions';
+import { IStore } from '../../app/types';
 import { translate } from '../../base/i18n/functions';
 import Icon from '../../base/icons/components/Icon';
 import { IconPlus } from '../../base/icons/svg';
 import Tooltip from '../../base/tooltip/components/Tooltip';
-import { updateCalendarEvent } from '../actions';
+import { updateCalendarEvent } from '../actions.web';
 
 /**
  * The type of the React {@code Component} props of {@link AddMeetingUrlButton}.
  */
-type Props = {
+interface IProps extends WithTranslation {
 
     /**
      * The calendar ID associated with the calendar event.
      */
-    calendarId: string,
+    calendarId: string;
 
     /**
      * Invoked to add a meeting URL to a calendar event.
      */
-    dispatch: Dispatch<any>,
+    dispatch: IStore['dispatch'];
 
     /**
      * The ID of the calendar event that will have a meeting URL added on click.
      */
-    eventId: string,
-
-    /**
-     * Invoked to obtain translated strings.
-     */
-    t: Function
-};
+    eventId: string;
+}
 
 /**
  * A React Component for adding a meeting URL to an existing calendar event.
  *
  * @augments Component
  */
-class AddMeetingUrlButton extends Component<Props> {
+class AddMeetingUrlButton extends Component<IProps> {
     /**
      * Initializes a new {@code AddMeetingUrlButton} instance.
      *
      * @inheritdoc
      */
-    constructor(props: Props) {
+    constructor(props: IProps) {
         super(props);
 
         // Bind event handler so it is only bound once for every instance.
@@ -76,8 +70,6 @@ class AddMeetingUrlButton extends Component<Props> {
         );
     }
 
-    _onClick: () => void;
-
     /**
      * Dispatches an action to adding a meeting URL to a calendar event.
      *
@@ -91,8 +83,6 @@ class AddMeetingUrlButton extends Component<Props> {
         dispatch(updateCalendarEvent(eventId, calendarId));
     }
 
-    _onKeyPress: (Object) => void;
-
     /**
      * KeyPress handler for accessibility.
      *
@@ -100,7 +90,7 @@ class AddMeetingUrlButton extends Component<Props> {
      *
      * @returns {void}
      */
-    _onKeyPress(e) {
+    _onKeyPress(e: React.KeyboardEvent) {
         if (e.key === ' ' || e.key === 'Enter') {
             e.preventDefault();
             this._onClick();
diff --git a/react/features/calendar-sync/components/CalendarList.web.js b/react/features/calendar-sync/components/CalendarList.web.tsx
similarity index 89%
rename from react/features/calendar-sync/components/CalendarList.web.js
rename to react/features/calendar-sync/components/CalendarList.web.tsx
index 6a57b61e6f..eaad42ddfe 100644
--- a/react/features/calendar-sync/components/CalendarList.web.js
+++ b/react/features/calendar-sync/components/CalendarList.web.tsx
@@ -1,71 +1,64 @@
-// @flow
-
 import React from 'react';
+import { WithTranslation } from 'react-i18next';
 import { connect } from 'react-redux';
 
 import { createCalendarClickedEvent } from '../../analytics/AnalyticsEvents';
 import { sendAnalytics } from '../../analytics/functions';
+import { IReduxState } from '../../app/types';
 import { translate } from '../../base/i18n/functions';
 import Icon from '../../base/icons/components/Icon';
 import { IconCalendar } from '../../base/icons/svg';
 import AbstractPage from '../../base/react/components/AbstractPage';
 import Spinner from '../../base/ui/components/web/Spinner';
-import { openSettingsDialog } from '../../settings/actions';
+import { openSettingsDialog } from '../../settings/actions.web';
 import { SETTINGS_TABS } from '../../settings/constants';
-import { refreshCalendar } from '../actions';
+import { refreshCalendar } from '../actions.web';
 import { ERRORS } from '../constants';
 
-import CalendarListContent from './CalendarListContent';
-
-declare var interfaceConfig: Object;
+import CalendarListContent from './CalendarListContent.web';
 
 /**
  * The type of the React {@code Component} props of {@link CalendarList}.
  */
-type Props = {
+interface IProps extends WithTranslation {
 
     /**
      * The error object containing details about any error that has occurred
      * while interacting with calendar integration.
      */
-    _calendarError: ?Object,
+    _calendarError?: { error: string; };
 
     /**
      * Whether or not a calendar may be connected for fetching calendar events.
      */
-    _hasIntegrationSelected: boolean,
+    _hasIntegrationSelected: boolean;
 
     /**
      * Whether or not events have been fetched from a calendar.
      */
-    _hasLoadedEvents: boolean,
+    _hasLoadedEvents: boolean;
 
     /**
      * Indicates if the list is disabled or not.
      */
-    disabled: boolean,
+    disabled?: boolean;
 
     /**
      * The Redux dispatch function.
      */
-    dispatch: Function,
-
-    /**
-     * The translate function.
-     */
-    t: Function
-};
+    dispatch: Function;
+}
 
 /**
  * Component to display a list of events from the user's calendar.
  */
-class CalendarList extends AbstractPage<Props> {
+class CalendarList extends AbstractPage<IProps> {
     /**
      * Initializes a new {@code CalendarList} instance.
      *
      * @inheritdoc
      */
-    constructor(props) {
+    constructor(props: IProps) {
         super(props);
 
         // Bind event handlers so they are only bound once per instance.
@@ -87,7 +80,7 @@ class CalendarList extends AbstractPage<Props> {
         return (
             CalendarListContent
                 ? <CalendarListContent
-                    disabled = { disabled }
+                    disabled = { Boolean(disabled) }
                     listEmptyComponent
                         = { this._getRenderListEmptyComponent() } />
                 : null
@@ -102,7 +95,7 @@ class CalendarList extends AbstractPage<Props> {
      * @returns {React$Component}
      */
     _getErrorMessage() {
-        const { _calendarError = {}, t } = this.props;
+        const { _calendarError = { error: undefined }, t } = this.props;
 
         let errorMessageKey = 'calendarSync.error.generic';
         let showRefreshButton = true;
@@ -142,8 +135,6 @@ class CalendarList extends AbstractPage<Props> {
         );
     }
 
-    _getRenderListEmptyComponent: () => Object;
-
     /**
      * Returns a list empty component if a custom one has to be rendered instead
      * of the default one in the {@link NavigateSectionList}.
@@ -210,8 +201,6 @@ class CalendarList extends AbstractPage<Props> {
         );
     }
 
-    _onOpenSettings: () => void;
-
     /**
      * Opens {@code SettingsDialog}.
      *
@@ -224,8 +213,6 @@ class CalendarList extends AbstractPage<Props> {
         this.props.dispatch(openSettingsDialog(SETTINGS_TABS.CALENDAR));
     }
 
-    _onKeyPressOpenSettings: (Object) => void;
-
     /**
      * KeyPress handler for accessibility.
      *
@@ -233,15 +220,13 @@ class CalendarList extends AbstractPage<Props> {
      *
      * @returns {void}
      */
-    _onKeyPressOpenSettings(e) {
+    _onKeyPressOpenSettings(e: React.KeyboardEvent) {
         if (e.key === ' ' || e.key === 'Enter') {
             e.preventDefault();
             this._onOpenSettings();
         }
     }
 
-    _onRefreshEvents: () => void;
-
 
     /**
      * Gets an updated list of calendar events.
@@ -266,7 +251,7 @@ class CalendarList extends AbstractPage<Props> {
  *     _hasLoadedEvents: boolean
  * }}
  */
-function _mapStateToProps(state) {
+function _mapStateToProps(state: IReduxState) {
     const {
         error,
         events,
diff --git a/react/features/calendar-sync/components/CalendarListContent.web.js b/react/features/calendar-sync/components/CalendarListContent.web.tsx
similarity index 84%
rename from react/features/calendar-sync/components/CalendarListContent.web.js
rename to react/features/calendar-sync/components/CalendarListContent.web.tsx
index 7f2e14b383..9ab7b746cc 100644
--- a/react/features/calendar-sync/components/CalendarListContent.web.js
+++ b/react/features/calendar-sync/components/CalendarListContent.web.tsx
@@ -1,47 +1,46 @@
-// @flow
-
 import React, { Component } from 'react';
 import { connect } from 'react-redux';
 
 import { createCalendarClickedEvent, createCalendarSelectedEvent } from '../../analytics/AnalyticsEvents';
 import { sendAnalytics } from '../../analytics/functions';
-import { appNavigate } from '../../app/actions';
+import { appNavigate } from '../../app/actions.web';
+import { IReduxState } from '../../app/types';
 import MeetingsList from '../../base/react/components/web/MeetingsList';
 
-import AddMeetingUrlButton from './AddMeetingUrlButton';
-import JoinButton from './JoinButton';
+import AddMeetingUrlButton from './AddMeetingUrlButton.web';
+import JoinButton from './JoinButton.web';
 
 /**
  * The type of the React {@code Component} props of
  * {@link CalendarListContent}.
  */
-type Props = {
+interface IProps {
 
     /**
      * The calendar event list.
      */
-    _eventList: Array<Object>,
+    _eventList: Array<Object>;
 
     /**
      * Indicates if the list is disabled or not.
      */
-    disabled: boolean,
+    disabled: boolean;
 
     /**
      * The Redux dispatch function.
      */
-    dispatch: Function,
+    dispatch: Function;
 
     /**
      *
      */
-    listEmptyComponent: React$Node,
-};
+    listEmptyComponent: React.ReactNode;
+}
 
 /**
  * Component to display a list of events from a connected calendar.
  */
-class CalendarListContent extends Component<Props> {
+class CalendarListContent extends Component<IProps> {
     /**
      * Default values for the component's props.
      */
@@ -54,7 +53,7 @@ class CalendarListContent extends Component<Props> {
      *
      * @inheritdoc
      */
-    constructor(props: Props) {
+    constructor(props: IProps) {
         super(props);
 
         // Bind event handlers so they are only bound once per instance.
@@ -93,8 +92,6 @@ class CalendarListContent extends Component<Props> {
         );
     }
 
-    _onJoinPress: (Object, string) => Function;
-
     /**
      * Handles the list's navigate action.
      *
@@ -103,14 +100,12 @@ class CalendarListContent extends Component<Props> {
      * @param {string} url - The url string to navigate to.
      * @returns {void}
      */
-    _onJoinPress(event, url) {
+    _onJoinPress(event: React.KeyboardEvent, url: string) {
         event.stopPropagation();
 
         this._onPress(url, 'meeting.join');
     }
 
-    _onPress: (string, ?string) => Function;
-
     /**
      * Handles the list's navigate action.
      *
@@ -120,14 +115,12 @@ class CalendarListContent extends Component<Props> {
      * associated with this action.
      * @returns {void}
      */
-    _onPress(url, analyticsEventName = 'meeting.tile') {
+    _onPress(url: string, analyticsEventName = 'meeting.tile') {
         sendAnalytics(createCalendarClickedEvent(analyticsEventName));
 
         this.props.dispatch(appNavigate(url));
     }
 
-    _toDisplayableItem: Object => Object;
-
     /**
      * Creates a displayable object from an event.
      *
@@ -135,7 +128,7 @@ class CalendarListContent extends Component<Props> {
      * @private
      * @returns {Object}
      */
-    _toDisplayableItem(event) {
+    _toDisplayableItem(event: any) {
         return {
             elementAfter: event.url
                 ? <JoinButton
@@ -161,7 +154,7 @@ class CalendarListContent extends Component<Props> {
  *     _eventList: Array<Object>
  * }}
  */
-function _mapStateToProps(state: Object) {
+function _mapStateToProps(state: IReduxState) {
     return {
         _eventList: state['features/calendar-sync'].events
     };
diff --git a/react/features/calendar-sync/components/JoinButton.web.js b/react/features/calendar-sync/components/JoinButton.web.tsx
similarity index 86%
rename from react/features/calendar-sync/components/JoinButton.web.js
rename to react/features/calendar-sync/components/JoinButton.web.tsx
index 3caa39a475..f8452dffa2 100644
--- a/react/features/calendar-sync/components/JoinButton.web.js
+++ b/react/features/calendar-sync/components/JoinButton.web.tsx
@@ -1,6 +1,5 @@
-// @flow
-
 import React, { Component } from 'react';
+import { WithTranslation } from 'react-i18next';
 
 import { translate } from '../../base/i18n/functions';
 import Icon from '../../base/icons/components/Icon';
@@ -10,30 +9,25 @@ import Tooltip from '../../base/tooltip/components/Tooltip';
 /**
  * The type of the React {@code Component} props of {@link JoinButton}.
  */
-type Props = {
+interface IProps extends WithTranslation {
 
     /**
      * The function called when the button is pressed.
      */
-    onPress: Function,
+    onPress: Function;
 
     /**
      * The meeting URL associated with the {@link JoinButton} instance.
      */
-    url: string,
-
-    /**
-     * Invoked to obtain translated strings.
-     */
-    t: Function
-};
+    url: string;
+}
 
 /**
  * A React Component for joining an existing calendar meeting.
  *
  * @augments Component
  */
-class JoinButton extends Component<Props> {
+class JoinButton extends Component<IProps> {
 
     /**
      * Initializes a new {@code JoinButton} instance.
@@ -41,7 +35,7 @@ class JoinButton extends Component<Props> {
      * @param {*} props - The read-only properties with which the new instance
      * is to be initialized.
      */
-    constructor(props) {
+    constructor(props: IProps) {
         super(props);
 
         // Bind event handler so it is only bound once for every instance.
@@ -73,8 +67,6 @@ class JoinButton extends Component<Props> {
         );
     }
 
-    _onClick: (Object) => void;
-
     /**
      * Callback invoked when the component is clicked.
      *
@@ -82,12 +74,10 @@ class JoinButton extends Component<Props> {
      * @private
      * @returns {void}
      */
-    _onClick(event) {
+    _onClick(event?: React.MouseEvent) {
         this.props.onPress(event, this.props.url);
     }
 
-    _onKeyPress: (Object) => void;
-
     /**
      * KeyPress handler for accessibility.
      *
@@ -95,7 +85,7 @@ class JoinButton extends Component<Props> {
      *
      * @returns {void}
      */
-    _onKeyPress(e) {
+    _onKeyPress(e: React.KeyboardEvent) {
         if (e.key === ' ' || e.key === 'Enter') {
             e.preventDefault();
             this._onClick();
diff --git a/react/features/calendar-sync/reducer.tsx b/react/features/calendar-sync/reducer.tsx
index f31c453624..0b6950d639 100644
--- a/react/features/calendar-sync/reducer.tsx
+++ b/react/features/calendar-sync/reducer.tsx
@@ -28,7 +28,7 @@ const DEFAULT_STATE = {
 
 export interface ICalendarSyncState {
     authorization?: string;
-    error?: Object;
+    error?: { error: string; };
     events: Array<{
         calendarId: string;
         endDate: string;
diff --git a/react/features/chrome-extension-banner/components/ChromeExtensionBanner.web.js b/react/features/chrome-extension-banner/components/ChromeExtensionBanner.web.tsx
similarity index 90%
rename from react/features/chrome-extension-banner/components/ChromeExtensionBanner.web.js
rename to react/features/chrome-extension-banner/components/ChromeExtensionBanner.web.tsx
index 1a28a68edf..be41282a49 100644
--- a/react/features/chrome-extension-banner/components/ChromeExtensionBanner.web.js
+++ b/react/features/chrome-extension-banner/components/ChromeExtensionBanner.web.tsx
@@ -1,13 +1,15 @@
-// @flow
-
+// @ts-expect-error
 import { jitsiLocalStorage } from '@jitsi/js-utils';
 import React, { PureComponent } from 'react';
+import { WithTranslation } from 'react-i18next';
 import { connect } from 'react-redux';
 
 import { createChromeExtensionBannerEvent } from '../../analytics/AnalyticsEvents';
 import { sendAnalytics } from '../../analytics/functions';
+import { IReduxState } from '../../app/types';
 import { getCurrentConference } from '../../base/conference/functions';
-import checkChromeExtensionsInstalled from '../../base/environment/checkChromeExtensionsInstalled';
+import { IJitsiConference } from '../../base/conference/reducer';
+import checkChromeExtensionsInstalled from '../../base/environment/checkChromeExtensionsInstalled.web';
 import {
     isMobileBrowser
 } from '../../base/environment/utils';
@@ -18,9 +20,6 @@ import { browser } from '../../base/lib-jitsi-meet';
 import { isVpaasMeeting } from '../../jaas/functions';
 import logger from '../logger';
 
-
-declare var interfaceConfig: Object;
-
 const emptyObject = {};
 
 /**
@@ -33,54 +32,53 @@ const DONT_SHOW_AGAIN_CHECKED = 'hide_chrome_extension_banner';
 /**
  * The type of the React {@code PureComponent} props of {@link ChromeExtensionBanner}.
  */
-type Props = {
+interface IProps extends WithTranslation {
 
     /**
      * Contains info about installed/to be installed chrome extension(s).
      */
-    bannerCfg: Object,
+    bannerCfg: {
+        chromeExtensionsInfo?: string[];
+        edgeUrl?: string;
+        url?: string;
+    };
 
     /**
      * Conference data, if any.
      */
-    conference: Object,
+    conference?: IJitsiConference;
 
     /**
      * Whether I am the current recorder.
      */
-    iAmRecorder: boolean,
+    iAmRecorder: boolean;
 
     /**
      * Whether it's a vpaas meeting or not.
      */
-    isVpaas: boolean,
-
-    /**
-     * Invoked to obtain translated strings.
-     */
-    t: Function,
-};
+    isVpaas: boolean;
+}
 
 /**
  * The type of the React {@link PureComponent} state of {@link ChromeExtensionBanner}.
  */
-type State = {
-
-    /**
-     * Keeps the current value of dont show again checkbox.
-     */
-    dontShowAgainChecked: boolean,
+interface IState {
 
     /**
      * Tells whether user pressed install extension or close button.
      */
-    closePressed: boolean,
+    closePressed: boolean;
+
+    /**
+     * Keeps the current value of dont show again checkbox.
+     */
+    dontShowAgainChecked: boolean;
 
     /**
      * Tells whether should show the banner or not based on extension being installed or not.
      */
-    shouldShow: boolean,
-};
+    shouldShow: boolean;
+}
 
 /**
  * Implements a React {@link PureComponent} which displays a banner having a link to the chrome extension.
@@ -88,14 +86,16 @@ type State = {
  * @class ChromeExtensionBanner
  * @augments PureComponent
  */
-class ChromeExtensionBanner extends PureComponent<Props, State> {
+class ChromeExtensionBanner extends PureComponent<IProps, IState> {
+    isEdge: boolean;
+
     /**
      * Initializes a new {@code ChromeExtensionBanner} instance.
      *
      * @param {Object} props - The read-only React {@code PureComponent} props with
      * which the new instance is to be initialized.
      */
-    constructor(props: Props) {
+    constructor(props: IProps) {
         super(props);
         this.state = {
             dontShowAgainChecked: false,
@@ -118,7 +118,7 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
      *
      * @inheritdoc
      */
-    async componentDidUpdate(prevProps) {
+    async componentDidUpdate(prevProps: IProps) {
         if (!this._isSupportedEnvironment()) {
             return;
         }
@@ -137,8 +137,7 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
         const hasExtensions = await checkChromeExtensionsInstalled(this.props.bannerCfg);
 
         if (
-            hasExtensions
-            && hasExtensions.length
+            hasExtensions?.length
             && hasExtensions.every(ext => !ext)
             && !this.state.shouldShow
         ) {
@@ -160,8 +159,6 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
             && !this.props.isVpaas;
     }
 
-    _onClosePressed: () => void;
-
     /**
      * Closes the banner for the current session.
      *
@@ -172,8 +169,6 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
         this.setState({ closePressed: true });
     }
 
-    _onCloseKeyPress: (Object) => void;
-
     /**
      * KeyPress handler for accessibility.
      *
@@ -181,15 +176,13 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
      *
      * @returns {void}
      */
-    _onCloseKeyPress(e) {
+    _onCloseKeyPress(e: React.KeyboardEvent) {
         if (e.key === ' ' || e.key === 'Enter') {
             e.preventDefault();
             this._onClosePressed();
         }
     }
 
-    _onInstallExtensionClick: () => void;
-
     /**
      * Opens the chrome extension page.
      *
@@ -203,8 +196,6 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
         this.setState({ closePressed: true });
     }
 
-    _onInstallExtensionKeyPress: (Object) => void;
-
     /**
      * KeyPress handler for accessibility.
      *
@@ -212,15 +203,13 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
      *
      * @returns {void}
      */
-    _onInstallExtensionKeyPress(e) {
+    _onInstallExtensionKeyPress(e: React.KeyboardEvent) {
         if (e.key === ' ' || e.key === 'Enter') {
             e.preventDefault();
             this._onClosePressed();
         }
     }
 
-    _shouldNotRender: () => boolean;
-
     /**
      * Checks whether the banner should not be rendered.
      *
@@ -240,15 +229,13 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
             || this.props.iAmRecorder;
     }
 
-    _onDontShowAgainChange: (object: Object) => void;
-
     /**
     * Handles the current `don't show again` checkbox state.
     *
     * @param {Object} event - Input change event.
     * @returns {void}
     */
-    _onDontShowAgainChange(event) {
+    _onDontShowAgainChange(event: React.ChangeEvent<HTMLInputElement>) {
         this.setState({ dontShowAgainChecked: event.target.checked });
     }
 
@@ -258,7 +245,7 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
      * @inheritdoc
      * @returns {ReactElement}
      */
-    render() {
+    render(): React.ReactNode {
         if (this._shouldNotRender()) {
             if (this.state.dontShowAgainChecked) {
                 jitsiLocalStorage.setItem(DONT_SHOW_AGAIN_CHECKED, 'true');
@@ -340,12 +327,12 @@ class ChromeExtensionBanner extends PureComponent<Props, State> {
  * @param {Object} state - Redux state.
  * @returns {Object}
  */
-const _mapStateToProps = state => {
+const _mapStateToProps = (state: IReduxState) => {
     return {
         // Using emptyObject so that we don't change the reference every time when _mapStateToProps is called.
         bannerCfg: state['features/base/config'].chromeExtensionBanner || emptyObject,
         conference: getCurrentConference(state),
-        iAmRecorder: state['features/base/config'].iAmRecorder,
+        iAmRecorder: Boolean(state['features/base/config'].iAmRecorder),
         isVpaas: isVpaasMeeting(state)
     };
 };
diff --git a/react/features/deep-linking/functions.ts b/react/features/deep-linking/functions.ts
index a1c2e43c36..685fc5eac2 100644
--- a/react/features/deep-linking/functions.ts
+++ b/react/features/deep-linking/functions.ts
@@ -60,6 +60,8 @@ export function getDeepLinkingPage(state: IReduxState) {
     const { room } = state['features/base/conference'];
     const { launchInWeb } = state['features/deep-linking'];
     const deeplinking = state['features/base/config'].deeplinking || {};
+
+    // @ts-ignore
     const { appScheme } = deeplinking?.[Platform.OS as keyof typeof deeplinking] || {};
 
     // Show only if we are about to join a conference.
diff --git a/react/features/recent-list/components/RecentList.web.js b/react/features/recent-list/components/RecentList.web.tsx
similarity index 80%
rename from react/features/recent-list/components/RecentList.web.js
rename to react/features/recent-list/components/RecentList.web.tsx
index 379bad8d6c..35a6d2d299 100644
--- a/react/features/recent-list/components/RecentList.web.js
+++ b/react/features/recent-list/components/RecentList.web.tsx
@@ -1,56 +1,47 @@
-// @flow
-
 import React from 'react';
+import { WithTranslation } from 'react-i18next';
 import { connect } from 'react-redux';
-import type { Dispatch } from 'redux';
 
+import { IReduxState, IStore } from '../../app/types';
 import { translate } from '../../base/i18n/functions';
 import MeetingsList from '../../base/react/components/web/MeetingsList';
 import { deleteRecentListEntry } from '../actions';
-import { isRecentListEnabled, toDisplayableList } from '../functions';
+import { isRecentListEnabled, toDisplayableList } from '../functions.web';
 
 import AbstractRecentList from './AbstractRecentList';
 
 /**
  * The type of the React {@code Component} props of {@link RecentList}.
  */
-type Props = {
-
-    /**
-     * Renders the list disabled.
-     */
-    disabled: boolean,
-
-    /**
-     * The redux store's {@code dispatch} function.
-     */
-    dispatch: Dispatch<any>,
-
-    /**
-     * The translate function.
-     */
-    t: Function,
+interface IProps extends WithTranslation {
 
     /**
      * The recent list from the Redux store.
      */
-    _recentList: Array<Object>
-};
+    _recentList: Array<any>;
+
+    /**
+     * Renders the list disabled.
+     */
+    disabled?: boolean;
+
+    /**
+     * The redux store's {@code dispatch} function.
+     */
+    dispatch: IStore['dispatch'];
+}
 
 /**
  * The cross platform container rendering the list of the recently joined rooms.
  *
  */
-class RecentList extends AbstractRecentList<Props> {
-    _getRenderListEmptyComponent: () => React$Node;
-    _onPress: string => {};
-
+class RecentList extends AbstractRecentList<IProps> {
     /**
      * Initializes a new {@code RecentList} instance.
      *
      * @inheritdoc
      */
-    constructor(props: Props) {
+    constructor(props: IProps) {
         super(props);
 
         this._getRenderListEmptyComponent
@@ -59,15 +50,13 @@ class RecentList extends AbstractRecentList<Props> {
         this._onItemDelete = this._onItemDelete.bind(this);
     }
 
-    _onItemDelete: Object => void;
-
     /**
      * Deletes a recent entry.
      *
      * @param {Object} entry - The entry to be deleted.
      * @inheritdoc
      */
-    _onItemDelete(entry) {
+    _onItemDelete(entry: Object) {
         this.props.dispatch(deleteRecentListEntry(entry));
     }
 
@@ -88,7 +77,7 @@ class RecentList extends AbstractRecentList<Props> {
 
         return (
             <MeetingsList
-                disabled = { disabled }
+                disabled = { Boolean(disabled) }
                 hideURL = { true }
                 listEmptyComponent = { this._getRenderListEmptyComponent() }
                 meetings = { recentList }
@@ -107,7 +96,7 @@ class RecentList extends AbstractRecentList<Props> {
  *     _recentList: Array
  * }}
  */
-export function _mapStateToProps(state: Object) {
+export function _mapStateToProps(state: IReduxState) {
     return {
         _recentList: state['features/recent-list']
     };
diff --git a/react/features/unsupported-browser/components/DefaultUnsupportedDesktopBrowser.js b/react/features/unsupported-browser/components/DefaultUnsupportedDesktopBrowser.tsx
similarity index 98%
rename from react/features/unsupported-browser/components/DefaultUnsupportedDesktopBrowser.js
rename to react/features/unsupported-browser/components/DefaultUnsupportedDesktopBrowser.tsx
index c62c0fdaeb..68b3f9cb48 100644
--- a/react/features/unsupported-browser/components/DefaultUnsupportedDesktopBrowser.js
+++ b/react/features/unsupported-browser/components/DefaultUnsupportedDesktopBrowser.tsx
@@ -1,5 +1,3 @@
-/* @flow */
-
 import React, { Component } from 'react';
 
 /**
diff --git a/react/features/unsupported-browser/components/UnsupportedDesktopBrowser.js b/react/features/unsupported-browser/components/UnsupportedDesktopBrowser.ts
similarity index 100%
rename from react/features/unsupported-browser/components/UnsupportedDesktopBrowser.js
rename to react/features/unsupported-browser/components/UnsupportedDesktopBrowser.ts
diff --git a/react/features/welcome/components/AbstractWelcomePage.ts b/react/features/welcome/components/AbstractWelcomePage.ts
index c6b5929f91..dd12714264 100644
--- a/react/features/welcome/components/AbstractWelcomePage.ts
+++ b/react/features/welcome/components/AbstractWelcomePage.ts
@@ -1,6 +1,7 @@
 // @ts-expect-error
 import { generateRoomWithoutSeparator } from '@jitsi/js-utils/random';
 import { Component } from 'react';
+import { WithTranslation } from 'react-i18next';
 
 import { createWelcomePageEvent } from '../../analytics/AnalyticsEvents';
 import { sendAnalytics } from '../../analytics/functions';
@@ -14,7 +15,7 @@ import { isRecentListEnabled } from '../../recent-list/functions';
 /**
  * {@code AbstractWelcomePage}'s React {@code Component} prop types.
  */
-export interface IProps {
+export interface IProps extends WithTranslation {
 
     /**
      * Whether the calendar functionality is enabled or not.
@@ -57,12 +58,23 @@ export interface IProps {
     dispatch: IStore['dispatch'];
 }
 
+interface IState {
+    animateTimeoutId?: number;
+    generateRoomNames?: string;
+    generatedRoomName: string;
+    insecureRoomName: boolean;
+    joining: boolean;
+    room: string;
+    roomPlaceholder: string;
+    updateTimeoutId?: number;
+}
+
 /**
  * Base (abstract) class for container component rendering the welcome page.
  *
  * @abstract
  */
-export class AbstractWelcomePage<P extends IProps> extends Component<P> {
+export class AbstractWelcomePage<P extends IProps> extends Component<P, IState> {
     _mounted: boolean | undefined;
 
     /**
@@ -81,6 +93,7 @@ export class AbstractWelcomePage<P extends IProps> extends Component<P> {
     state = {
         animateTimeoutId: undefined,
         generatedRoomName: '',
+        generateRoomNames: undefined,
         insecureRoomName: false,
         joining: false,
         room: '',
@@ -142,7 +155,7 @@ export class AbstractWelcomePage<P extends IProps> extends Component<P> {
 
         if (word.length > 1) {
             animateTimeoutId
-                = setTimeout(
+                = window.setTimeout(
                     () => {
                         this._animateRoomNameChanging(
                             word.substring(1, word.length));
@@ -171,7 +184,9 @@ export class AbstractWelcomePage<P extends IProps> extends Component<P> {
      *
      * @returns {ReactElement}
      */
-    _doRenderInsecureRoomNameWarning: () => React.Component<any>;
+    _doRenderInsecureRoomNameWarning(): JSX.Element | null {
+        return null;
+    }
 
     /**
      * Handles joining. Either by clicking on 'Join' button
@@ -213,7 +228,7 @@ export class AbstractWelcomePage<P extends IProps> extends Component<P> {
     _onRoomChange(value: string) {
         this.setState({
             room: value,
-            insecureRoomName: this.props._enableInsecureRoomNameWarning && value && isInsecureRoomName(value)
+            insecureRoomName: Boolean(this.props._enableInsecureRoomNameWarning && value && isInsecureRoomName(value))
         });
     }
 
@@ -240,7 +255,7 @@ export class AbstractWelcomePage<P extends IProps> extends Component<P> {
     _updateRoomName() {
         const generatedRoomName = generateRoomWithoutSeparator();
         const roomPlaceholder = '';
-        const updateTimeoutId = setTimeout(this._updateRoomName, 10000);
+        const updateTimeoutId = window.setTimeout(this._updateRoomName, 10000);
 
         this._clearTimeouts();
         this.setState(
@@ -268,7 +283,7 @@ export function _mapStateToProps(state: IReduxState) {
         _enableInsecureRoomNameWarning: state['features/base/config'].enableInsecureRoomNameWarning || false,
         _moderatedRoomServiceUrl: state['features/base/config'].moderatedRoomServiceUrl,
         _recentListEnabled: isRecentListEnabled(),
-        _room: state['features/base/conference'].room,
+        _room: state['features/base/conference'].room ?? '',
         _settings: state['features/base/settings']
     };
 }
diff --git a/react/features/welcome/components/BlankPage.web.js b/react/features/welcome/components/BlankPage.web.ts
similarity index 100%
rename from react/features/welcome/components/BlankPage.web.js
rename to react/features/welcome/components/BlankPage.web.ts
diff --git a/react/features/welcome/components/Tabs.js b/react/features/welcome/components/Tabs.tsx
similarity index 89%
rename from react/features/welcome/components/Tabs.js
rename to react/features/welcome/components/Tabs.tsx
index 70ba7ac9e4..f7b4d8e1ee 100644
--- a/react/features/welcome/components/Tabs.js
+++ b/react/features/welcome/components/Tabs.tsx
@@ -1,37 +1,40 @@
-// @flow
 import React, { useCallback, useEffect, useState } from 'react';
 
 /**
  * The type of the React {@code Component} props of {@link Tabs}.
  */
-type Props = {
+interface IProps {
 
     /**
      * Accessibility label for the tabs container.
      *
      */
-    accessibilityLabel: string,
+    accessibilityLabel: string;
 
     /**
      * Tabs information.
      */
-    tabs: Object
-};
+    tabs: {
+        content: any;
+        id: string;
+        label: string;
+    }[];
+}
 
 /**
  * A React component that implements tabs.
  *
  * @returns {ReactElement} The component.
  */
-const Tabs = ({ accessibilityLabel, tabs }: Props) => {
+const Tabs = ({ accessibilityLabel, tabs }: IProps) => {
     const [ current, setCurrent ] = useState(0);
 
-    const onClick = useCallback(index => event => {
+    const onClick = useCallback(index => (event: React.MouseEvent) => {
         event.preventDefault();
         setCurrent(index);
     }, []);
 
-    const onKeyDown = useCallback(index => event => {
+    const onKeyDown = useCallback(index => (event: React.KeyboardEvent) => {
         let newIndex = null;
 
         if (event.key === 'ArrowLeft') {
@@ -52,6 +55,7 @@ const Tabs = ({ accessibilityLabel, tabs }: Props) => {
     useEffect(() => {
         // this test is needed to make sure the effect is triggered because of user actually changing tab
         if (document.activeElement?.getAttribute('role') === 'tab') {
+            // @ts-ignore
             document.querySelector(`#${`${tabs[current].id}-tab`}`)?.focus();
         }
 
diff --git a/react/features/welcome/components/WelcomePage.web.js b/react/features/welcome/components/WelcomePage.web.tsx
similarity index 90%
rename from react/features/welcome/components/WelcomePage.web.js
rename to react/features/welcome/components/WelcomePage.web.tsx
index 8d850c41c0..07b2a68982 100644
--- a/react/features/welcome/components/WelcomePage.web.js
+++ b/react/features/welcome/components/WelcomePage.web.tsx
@@ -1,5 +1,3 @@
-/* global interfaceConfig */
-
 import React from 'react';
 import { connect } from 'react-redux';
 
@@ -13,7 +11,7 @@ import RecentList from '../../recent-list/components/RecentList.web';
 import SettingsButton from '../../settings/components/web/SettingsButton';
 import { SETTINGS_TABS } from '../../settings/constants';
 
-import { AbstractWelcomePage, _mapStateToProps } from './AbstractWelcomePage';
+import { AbstractWelcomePage, IProps, _mapStateToProps } from './AbstractWelcomePage';
 import Tabs from './Tabs';
 
 /**
@@ -28,7 +26,15 @@ export const ROOM_NAME_VALIDATE_PATTERN_STR = '^[^?&:\u0022\u0027%#]+$';
  *
  * @augments AbstractWelcomePage
  */
-class WelcomePage extends AbstractWelcomePage {
+class WelcomePage extends AbstractWelcomePage<IProps> {
+    _additionalContentRef: HTMLDivElement | null;
+    _additionalToolbarContentRef: HTMLDivElement | null;
+    _additionalCardRef: HTMLDivElement | null;
+    _roomInputRef: HTMLInputElement | null;
+    _additionalCardTemplate: HTMLTemplateElement | null;
+    _additionalContentTemplate: HTMLTemplateElement | null;
+    _additionalToolbarContentTemplate: HTMLTemplateElement | null;
+
     /**
      * Default values for {@code WelcomePage} component's properties.
      *
@@ -44,7 +50,7 @@ class WelcomePage extends AbstractWelcomePage {
      * @param {Object} props - The read-only properties with which the new
      * instance is to be initialized.
      */
-    constructor(props) {
+    constructor(props: IProps) {
         super(props);
 
         this.state = {
@@ -83,7 +89,7 @@ class WelcomePage extends AbstractWelcomePage {
          * @type {HTMLTemplateElement|null}
          */
         this._additionalCardTemplate = document.getElementById(
-            'welcome-page-additional-card-template');
+            'welcome-page-additional-card-template') as HTMLTemplateElement;
 
         /**
          * The template to use as the main content for the welcome page. If
@@ -93,7 +99,7 @@ class WelcomePage extends AbstractWelcomePage {
          * @type {HTMLTemplateElement|null}
          */
         this._additionalContentTemplate = document.getElementById(
-            'welcome-page-additional-content-template');
+            'welcome-page-additional-content-template') as HTMLTemplateElement;
 
         /**
          * The template to use as the additional content for the welcome page header toolbar.
@@ -104,7 +110,7 @@ class WelcomePage extends AbstractWelcomePage {
          */
         this._additionalToolbarContentTemplate = document.getElementById(
             'settings-toolbar-additional-content-template'
-        );
+        ) as HTMLTemplateElement;
 
         // Bind event handlers so they are only bound once per instance.
         this._onFormSubmit = this._onFormSubmit.bind(this);
@@ -136,19 +142,19 @@ class WelcomePage extends AbstractWelcomePage {
         }
 
         if (this._shouldShowAdditionalContent()) {
-            this._additionalContentRef.appendChild(
-                this._additionalContentTemplate.content.cloneNode(true));
+            this._additionalContentRef?.appendChild(
+                this._additionalContentTemplate?.content.cloneNode(true) as Node);
         }
 
         if (this._shouldShowAdditionalToolbarContent()) {
-            this._additionalToolbarContentRef.appendChild(
-                this._additionalToolbarContentTemplate.content.cloneNode(true)
+            this._additionalToolbarContentRef?.appendChild(
+                this._additionalToolbarContentTemplate?.content.cloneNode(true) as Node
             );
         }
 
         if (this._shouldShowAdditionalCard()) {
-            this._additionalCardRef.appendChild(
-                this._additionalCardTemplate.content.cloneNode(true)
+            this._additionalCardRef?.appendChild(
+                this._additionalCardTemplate?.content.cloneNode(true) as Node
             );
         }
     }
@@ -236,7 +242,7 @@ class WelcomePage extends AbstractWelcomePage {
                                     className = 'welcome-page-button'
                                     id = 'enter_room_button'
                                     onClick = { this._onFormSubmit }
-                                    tabIndex = '0'
+                                    tabIndex = { 0 }
                                     type = 'button'>
                                     { t('welcomepage.startMeeting') }
                                 </button>
@@ -301,7 +307,7 @@ class WelcomePage extends AbstractWelcomePage {
      * @private
      * @returns {void}
      */
-    _onFormSubmit(event) {
+    _onFormSubmit(event: React.FormEvent) {
         event.preventDefault();
 
         if (!this._roomInputRef || this._roomInputRef.reportValidity()) {
@@ -319,7 +325,9 @@ class WelcomePage extends AbstractWelcomePage {
      * the EventTarget.
      * @protected
      */
-    _onRoomChange(event) {
+    // @ts-ignore
+    // eslint-disable-next-line require-jsdoc
+    _onRoomChange(event: React.ChangeEvent<HTMLInputElement>) {
         super._onRoomChange(event.target.value);
     }
 
@@ -332,8 +340,9 @@ class WelcomePage extends AbstractWelcomePage {
         const {
             t,
             _deeplinkingCfg: {
-                ios = {},
-                android = {}
+                ios = { downloadLink: undefined },
+                android = { fDroidUrl: undefined,
+                    downloadLink: undefined }
             }
         } = this.props;
 
@@ -424,7 +433,7 @@ class WelcomePage extends AbstractWelcomePage {
      * @private
      * @returns {void}
      */
-    _setAdditionalCardRef(el) {
+    _setAdditionalCardRef(el: HTMLDivElement) {
         this._additionalCardRef = el;
     }
 
@@ -437,7 +446,7 @@ class WelcomePage extends AbstractWelcomePage {
      * @private
      * @returns {void}
      */
-    _setAdditionalContentRef(el) {
+    _setAdditionalContentRef(el: HTMLDivElement) {
         this._additionalContentRef = el;
     }
 
@@ -450,7 +459,7 @@ class WelcomePage extends AbstractWelcomePage {
      * @private
      * @returns {void}
      */
-    _setAdditionalToolbarContentRef(el) {
+    _setAdditionalToolbarContentRef(el: HTMLDivElement) {
         this._additionalToolbarContentRef = el;
     }
 
@@ -462,7 +471,7 @@ class WelcomePage extends AbstractWelcomePage {
      * @private
      * @returns {void}
      */
-    _setRoomInputRef(el) {
+    _setRoomInputRef(el: HTMLInputElement) {
         this._roomInputRef = el;
     }