diff --git a/react/features/chat/middleware.ts b/react/features/chat/middleware.ts
index 0b4abf6e75..34a86b2243 100644
--- a/react/features/chat/middleware.ts
+++ b/react/features/chat/middleware.ts
@@ -678,6 +678,11 @@ function _shouldSendPrivateMessageTo(state: IReduxState, action: AnyAction) {
     }
 
     if (lastMessage.privateMessage) {
+        if (!lastMessage.participantId) {
+            // this is a system message we can ignore
+            return undefined;
+        }
+
         // We show the notice if the last received message was private.
         return {
             id: lastMessage.participantId,