diff --git a/react/features/base/dialog/components/Dialog.native.js b/react/features/base/dialog/components/Dialog.native.js
index 469c90cea7..ee68f082d9 100644
--- a/react/features/base/dialog/components/Dialog.native.js
+++ b/react/features/base/dialog/components/Dialog.native.js
@@ -173,6 +173,7 @@ class Dialog extends AbstractDialog<Props, State> {
                 if (style
                         && (style = StyleSheet.flatten(style))
                         && _TAG_KEY in style) {
+                    // $FlowFixMe
                     switch (style[_TAG_KEY]) {
                     case _SUBMIT_TEXT_TAG_VALUE:
                         if (this.state.submitting) {
diff --git a/react/features/base/jwt/components/CalleeInfo.js b/react/features/base/jwt/components/CalleeInfo.js
index 3fe5ee4962..58cbec4e3b 100644
--- a/react/features/base/jwt/components/CalleeInfo.js
+++ b/react/features/base/jwt/components/CalleeInfo.js
@@ -75,9 +75,9 @@ class CalleeInfo extends Component<Props, State> {
 
     _onLargeVideoAvatarVisible: Function;
 
-    _playAudioInterval: ?number;
+    _playAudioInterval: *;
 
-    _ringingTimeout: ?number
+    _ringingTimeout: *;
 
     _setAudio: Function;
 
diff --git a/react/features/base/media/components/native/VideoTransform.js b/react/features/base/media/components/native/VideoTransform.js
index 0fdb9510d7..ff814eafe4 100644
--- a/react/features/base/media/components/native/VideoTransform.js
+++ b/react/features/base/media/components/native/VideoTransform.js
@@ -3,6 +3,7 @@
 import React, { Component } from 'react';
 import { PanResponder, PixelRatio, View } from 'react-native';
 import { connect } from 'react-redux';
+import { type Dispatch } from 'redux';
 
 import { storeVideoTransform } from '../../actions';
 import styles from './styles';
@@ -684,7 +685,7 @@ class VideoTransform extends Component<Props, State> {
  *     _onUnmount: Function
  * }}
  */
-function _mapDispatchToProps(dispatch) {
+function _mapDispatchToProps(dispatch: Dispatch<*>) {
     return {
         /**
          * Dispatches actions to store the last applied transform to a video.
@@ -712,7 +713,7 @@ function _mapDispatchToProps(dispatch) {
 function _mapStateToProps(state) {
     return {
         /**
-         * The stored transforms retreived from Redux to be initially applied to
+         * The stored transforms retrieved from Redux to be initially applied to
          * different streams.
          *
          * @private
diff --git a/react/features/base/react/components/native/Header.js b/react/features/base/react/components/native/Header.js
index 98d1c5e712..91797d64f5 100644
--- a/react/features/base/react/components/native/Header.js
+++ b/react/features/base/react/components/native/Header.js
@@ -1,6 +1,6 @@
 // @flow
 
-import React, { Component } from 'react';
+import React, { Component, type Node } from 'react';
 import { Platform, SafeAreaView, StatusBar, View } from 'react-native';
 
 import styles, { HEADER_PADDING, STATUSBAR_COLOR } from './styles';
@@ -11,14 +11,14 @@ import styles, { HEADER_PADDING, STATUSBAR_COLOR } from './styles';
 const IOS10_PADDING = 20;
 
 /**
- * The type of the React {@code Component} props of {@link ScreenHeader}
+ * The type of the React {@code Component} props of {@link Header}
  */
 type Props = {
 
     /**
      * Children component(s).
      */
-    children: React$Node,
+    children: Node,
 
     /**
      * The component's external style
@@ -37,7 +37,7 @@ export default class Header extends Component<Props> {
      *
      * @returns {Object}
      */
-    static get buttonStyle() {
+    static get buttonStyle(): Object {
         return styles.headerButton;
     }
 
@@ -47,7 +47,7 @@ export default class Header extends Component<Props> {
      *
      * @returns {Object}
      */
-    static get pageStyle() {
+    static get pageStyle(): Object {
         return styles.page;
     }
 
@@ -56,7 +56,7 @@ export default class Header extends Component<Props> {
      *
      * @returns {Object}
      */
-    static get textStyle() {
+    static get textStyle(): Object {
         return styles.headerText;
     }
 
diff --git a/react/features/base/responsive-ui/actions.js b/react/features/base/responsive-ui/actions.js
index 867f5ce27a..5edf676b4b 100644
--- a/react/features/base/responsive-ui/actions.js
+++ b/react/features/base/responsive-ui/actions.js
@@ -29,7 +29,7 @@ const REDUCED_UI_THRESHOLD = 300;
  *     aspectRatio: Symbol
  * }}
  */
-export function setAspectRatio(width: number, height: number): Object {
+export function setAspectRatio(width: number, height: number): Function {
     return (dispatch: Dispatch<*>, getState: Function) => {
         // Don't change the aspect ratio if width and height are the same, that
         // is, if we transition to a 1:1 aspect ratio.
@@ -59,7 +59,7 @@ export function setAspectRatio(width: number, height: number): Object {
  *     reducedUI: boolean
  * }}
  */
-export function setReducedUI(width: number, height: number) {
+export function setReducedUI(width: number, height: number): Function {
     return (dispatch: Dispatch<*>, getState: Function) => {
         const reducedUI = Math.min(width, height) < REDUCED_UI_THRESHOLD;
 
diff --git a/react/features/base/responsive-ui/components/AspectRatioAware.js b/react/features/base/responsive-ui/components/AspectRatioAware.js
index 4254e3ff0c..c9db74e1de 100644
--- a/react/features/base/responsive-ui/components/AspectRatioAware.js
+++ b/react/features/base/responsive-ui/components/AspectRatioAware.js
@@ -58,6 +58,7 @@ export function makeAspectRatioAware(
         }
     }
 
+    // $FlowFixMe
     return connect(_mapStateToProps)(AspectRatioAware);
 }
 
diff --git a/react/features/base/responsive-ui/components/AspectRatioDetector.js b/react/features/base/responsive-ui/components/AspectRatioDetector.js
index 66bbdb9357..c3fb3d14d5 100644
--- a/react/features/base/responsive-ui/components/AspectRatioDetector.js
+++ b/react/features/base/responsive-ui/components/AspectRatioDetector.js
@@ -1,7 +1,8 @@
 // @flow
 
-import React, { Component } from 'react';
+import React, { Component, type Node } from 'react';
 import { connect } from 'react-redux';
+import { type Dispatch } from 'redux';
 
 import { setAspectRatio } from '../actions';
 import DimensionsDetector from './DimensionsDetector';
@@ -19,7 +20,7 @@ type Props = {
     /**
      * Any nested components.
      */
-    children: React$Node
+    children: Node
 };
 
 /**
@@ -51,7 +52,7 @@ class AspectRatioDetector extends Component<Props> {
  *     _onDimensionsChanged: Function
  * }}
  */
-function _mapDispatchToProps(dispatch) {
+function _mapDispatchToProps(dispatch: Dispatch<*>) {
     return {
         /**
          * Handles the "on dimensions changed" event and dispatches aspect ratio
diff --git a/react/features/base/responsive-ui/components/ReducedUIDetector.js b/react/features/base/responsive-ui/components/ReducedUIDetector.js
index 2c7f1c2c64..7b3aafc0a7 100644
--- a/react/features/base/responsive-ui/components/ReducedUIDetector.js
+++ b/react/features/base/responsive-ui/components/ReducedUIDetector.js
@@ -1,7 +1,8 @@
 // @flow
 
-import React, { Component } from 'react';
+import React, { Component, type Node } from 'react';
 import { connect } from 'react-redux';
+import { type Dispatch } from 'redux';
 
 import { setReducedUI } from '../actions';
 import DimensionsDetector from './DimensionsDetector';
@@ -20,7 +21,7 @@ type Props = {
     /**
      * Any nested components.
      */
-    children: React$Node
+    children: Node
 };
 
 /**
@@ -52,7 +53,7 @@ class ReducedUIDetector extends Component<Props> {
  *     _onDimensionsChanged: Function
  * }}
  */
-function _mapDispatchToProps(dispatch) {
+function _mapDispatchToProps(dispatch: Dispatch<*>) {
     return {
         /**
          * Handles the "on dimensions changed" event and dispatches the
diff --git a/react/features/base/testing/components/TestConnectionInfo.js b/react/features/base/testing/components/TestConnectionInfo.js
index be1d4ec57d..82e3de5543 100644
--- a/react/features/base/testing/components/TestConnectionInfo.js
+++ b/react/features/base/testing/components/TestConnectionInfo.js
@@ -81,8 +81,7 @@ type State = {
  * a good thing).
  */
 class TestConnectionInfo extends Component<Props, State> {
-
-    _onStatsUpdated: Object => void
+    _onStatsUpdated: Object => void;
 
     /**
      * Initializes new <tt>TestConnectionInfo</tt> instance.
diff --git a/react/features/calendar-sync/components/ConferenceNotification.native.js b/react/features/calendar-sync/components/ConferenceNotification.native.js
index 6ce2415919..5d391e0b59 100644
--- a/react/features/calendar-sync/components/ConferenceNotification.native.js
+++ b/react/features/calendar-sync/components/ConferenceNotification.native.js
@@ -56,14 +56,14 @@ type State = {
  * screen when another meeting is about to start.
  */
 class ConferenceNotification extends Component<Props, State> {
-    updateIntervalId: number;
+    updateIntervalId: *;
 
     /**
      * Constructor of the ConferenceNotification component.
      *
      * @inheritdoc
      */
-    constructor(props) {
+    constructor(props: Props) {
         super(props);
 
         this.state = {
@@ -97,7 +97,7 @@ class ConferenceNotification extends Component<Props, State> {
      * @inheritdoc
      */
     componentWillUnmount() {
-        clearTimeout(this.updateIntervalId);
+        clearInterval(this.updateIntervalId);
     }
 
     /**
@@ -160,7 +160,7 @@ class ConferenceNotification extends Component<Props, State> {
         return null;
     }
 
-    _getNotificationContentStyle: () => Array<Object>
+    _getNotificationContentStyle: () => Array<Object>;
 
     /**
      * Decides the color of the notification and some additional
@@ -251,7 +251,6 @@ class ConferenceNotification extends Component<Props, State> {
     /**
      * Opens the meeting URL that the notification shows.
      *
-     * @param {string} url - The URL to open.
      * @private
      * @returns {void}
      */
diff --git a/react/features/invite/components/InviteButton.native.js b/react/features/invite/components/InviteButton.native.js
index 48b2c231ac..c3c78eb185 100644
--- a/react/features/invite/components/InviteButton.native.js
+++ b/react/features/invite/components/InviteButton.native.js
@@ -1,6 +1,7 @@
 // @flow
 
 import { connect } from 'react-redux';
+import type { Dispatch } from 'redux';
 
 import { AbstractButton } from '../../base/toolbox';
 import type { AbstractButtonProps } from '../../base/toolbox';
@@ -105,7 +106,7 @@ class InviteButton extends AbstractButton<Props, *> {
  * }}
  * @private
  */
-function _mapDispatchToProps(dispatch) {
+function _mapDispatchToProps(dispatch: Dispatch<*>) {
     return {
         /**
          * Launches native invite dialog.
diff --git a/react/features/large-video/components/LargeVideoBackgroundCanvas.web.js b/react/features/large-video/components/LargeVideoBackgroundCanvas.web.js
index 30e0073b1a..cdf2a43a72 100644
--- a/react/features/large-video/components/LargeVideoBackgroundCanvas.web.js
+++ b/react/features/large-video/components/LargeVideoBackgroundCanvas.web.js
@@ -60,7 +60,7 @@ type Props = {
 export class LargeVideoBackgroundCanvas extends Component<Props> {
     _canvasEl: Object;
 
-    _updateCanvasInterval: number;
+    _updateCanvasInterval: *;
 
     /**
      * Initializes new {@code LargeVideoBackgroundCanvas} instance.
diff --git a/react/features/overlay/components/AbstractPageReloadOverlay.js b/react/features/overlay/components/AbstractPageReloadOverlay.js
index c2ddc0152f..eaceedc3b9 100644
--- a/react/features/overlay/components/AbstractPageReloadOverlay.js
+++ b/react/features/overlay/components/AbstractPageReloadOverlay.js
@@ -76,7 +76,7 @@ export default class AbstractPageReloadOverlay extends Component<*, *> {
      * @returns {boolean} - If this overlay needs to be rendered, {@code true};
      * {@code false}, otherwise.
      */
-    static needsRender(state) {
+    static needsRender(state: Object) {
         const conferenceError = state['features/base/conference'].error;
         const configError = state['features/base/config'].error;
         const connectionError = state['features/base/connection'].error;
@@ -88,7 +88,7 @@ export default class AbstractPageReloadOverlay extends Component<*, *> {
                 || configError);
     }
 
-    _interval: ?number
+    _interval: *;
 
     state: {
 
@@ -120,7 +120,7 @@ export default class AbstractPageReloadOverlay extends Component<*, *> {
          * @type {string}
          */
         title: string
-    }
+    };
 
     /**
      * Initializes a new AbstractPageReloadOverlay instance.
@@ -222,7 +222,7 @@ export default class AbstractPageReloadOverlay extends Component<*, *> {
     }
 
     /**
-     * Renders the button for relaod the page if necessary.
+     * Renders the button for reloading the page if necessary.
      *
      * @protected
      * @returns {ReactElement|null}
diff --git a/react/features/recording/components/RecordingLabel.web.js b/react/features/recording/components/RecordingLabel.web.js
index 392f97312e..69059384e3 100644
--- a/react/features/recording/components/RecordingLabel.web.js
+++ b/react/features/recording/components/RecordingLabel.web.js
@@ -98,7 +98,7 @@ type State = {
  * @extends {Component}
  */
 class RecordingLabel extends AbstractRecordingLabel<Props, State> {
-    _autohideTimeout: number;
+    _autohideTimeout: *;
 
     state = {
         hidden: false
diff --git a/react/features/speaker-stats/components/SpeakerStats.js b/react/features/speaker-stats/components/SpeakerStats.js
index 30e82f21b9..f9f0c0cdcd 100644
--- a/react/features/speaker-stats/components/SpeakerStats.js
+++ b/react/features/speaker-stats/components/SpeakerStats.js
@@ -45,7 +45,7 @@ class SpeakerStats extends Component<*, *> {
         stats: {}
     };
 
-    _updateInterval: number;
+    _updateInterval: *;
 
     /**
      * Initializes a new SpeakerStats instance.