diff --git a/js/signaling.js b/js/signaling.js
index 31b3c564bdb..1bbc97087d5 100644
--- a/js/signaling.js
+++ b/js/signaling.js
@@ -432,9 +432,10 @@
 
 		this._waitTimeUntilRetry = 1;
 
-		// Fetch more messages if PHP backend or a whole batch has been received
-		// (more messages might be available in this case).
-		if (this.receiveMessagesAgain || (messages && messages.length === this.chatBatchSize)) {
+		// Fetch more messages if PHP backend, or if the returned status is not
+		// "304 Not modified" (as in that case there could be more messages that
+		// need to be fetched).
+		if (this.receiveMessagesAgain || xhr.status !== 304) {
 			this._receiveChatMessages();
 		}
 
diff --git a/lib/Controller/ChatController.php b/lib/Controller/ChatController.php
index ed2437ecc80..b920f74780c 100644
--- a/lib/Controller/ChatController.php
+++ b/lib/Controller/ChatController.php
@@ -200,6 +200,15 @@ public function sendMessage(string $message, string $actorDisplayName = ''): Dat
 	 *   If messages have been returned (status=200) the new $lastKnownMessageId
 	 *   for the follow up query is available as `X-Chat-Last-Given` header.
 	 *
+	 * The limit specifies the maximum number of messages that will be returned,
+	 * although the actual number of returned messages could be lower if some
+	 * messages are not visible to the participant. Note that if none of the
+	 * messages are visible to the participant the returned number of messages
+	 * will be 0, yet the status will still be 200. Also note that
+	 * `X-Chat-Last-Given` may reference a message not visible and thus not
+	 * returned, but it should be used nevertheless as the $lastKnownMessageId
+	 * for the follow up query.
+	 *
 	 * @param int $lookIntoFuture Polling for new messages (1) or getting the history of the chat (0)
 	 * @param int $limit Number of chat messages to receive (100 by default, 200 at most)
 	 * @param int $lastKnownMessageId The last known message (serves as offset)
diff --git a/tests/integration/features/chat/commands.feature b/tests/integration/features/chat/commands.feature
new file mode 100644
index 00000000000..c2e81752c9b
--- /dev/null
+++ b/tests/integration/features/chat/commands.feature
@@ -0,0 +1,33 @@
+Feature: chat/commands
+  Background:
+    Given user "participant1" exists
+    Given user "participant2" exists
+
+  Scenario: user can see own help command and others can not
+    Given user "participant1" creates room "group room"
+      | roomType | 2 |
+      | roomName | room |
+    And user "participant1" adds "participant2" to room "group room" with 200
+    When user "participant1" sends message "/help" to room "group room" with 201
+    Then user "participant1" sees the following messages in room "group room" with 200
+      | room       | actorType | actorId | actorDisplayName | message                                    | messageParameters |
+      | group room | bots      | talk    | talk-bot         | There are currently no commands available. | []                |
+    And user "participant2" sees the following messages in room "group room" with 200
+
+  Scenario: user can see own help command along with regular messages and others can not
+    Given user "participant1" creates room "group room"
+      | roomType | 2 |
+      | roomName | room |
+    And user "participant1" adds "participant2" to room "group room" with 200
+    When user "participant1" sends message "Message 1" to room "group room" with 201
+    And user "participant1" sends message "/help" to room "group room" with 201
+    And user "participant1" sends message "Message 2" to room "group room" with 201
+    Then user "participant1" sees the following messages in room "group room" with 200
+      | room       | actorType | actorId      | actorDisplayName         | message                                    | messageParameters |
+      | group room | users     | participant1 | participant1-displayname | Message 2                                  | []                |
+      | group room | bots      | talk         | talk-bot                 | There are currently no commands available. | []                |
+      | group room | users     | participant1 | participant1-displayname | Message 1                                  | []                |
+    And user "participant2" sees the following messages in room "group room" with 200
+      | room       | actorType | actorId      | actorDisplayName         | message   | messageParameters |
+      | group room | users     | participant1 | participant1-displayname | Message 2 | []                |
+      | group room | users     | participant1 | participant1-displayname | Message 1 | []                |