diff --git a/packages/stream_chat/CHANGELOG.md b/packages/stream_chat/CHANGELOG.md
index f7094a53..f28d7e65 100644
--- a/packages/stream_chat/CHANGELOG.md
+++ b/packages/stream_chat/CHANGELOG.md
@@ -8,6 +8,8 @@
 ✅ Added
 
 - Expose `ChannelMute` class. [#1473](https://github.com/GetStream/stream-chat-flutter/issues/1473)
+- Added synchronization to the `StreamChatClient.sync`
+  api. [#1392](https://github.com/GetStream/stream-chat-flutter/issues/1392)
 
 ## 6.0.0
 
diff --git a/packages/stream_chat/lib/src/client/client.dart b/packages/stream_chat/lib/src/client/client.dart
index 26d229b4..72dfe989 100644
--- a/packages/stream_chat/lib/src/client/client.dart
+++ b/packages/stream_chat/lib/src/client/client.dart
@@ -32,6 +32,7 @@ import 'package:stream_chat/src/event_type.dart';
 import 'package:stream_chat/src/ws/connection_status.dart';
 import 'package:stream_chat/src/ws/websocket.dart';
 import 'package:stream_chat/version.dart';
+import 'package:synchronized/extension.dart';
 
 /// Handler function used for logging records. Function requires a single
 /// [LogRecord] as the only parameter.
@@ -488,37 +489,40 @@ class StreamChatClient {
 
   /// Get the events missed while offline to sync the offline storage
   /// Will automatically fetch [cids] and [lastSyncedAt] if [persistenceEnabled]
-  Future<void> sync({List<String>? cids, DateTime? lastSyncAt}) async {
-    cids ??= await _chatPersistenceClient?.getChannelCids();
-    if (cids == null || cids.isEmpty) {
-      return;
-    }
-
-    lastSyncAt ??= await _chatPersistenceClient?.getLastSyncAt();
-    if (lastSyncAt == null) {
-      return;
-    }
-
-    try {
-      final res = await _chatApi.general.sync(cids, lastSyncAt);
-      final events = res.events
-        ..sort((a, b) => a.createdAt.compareTo(b.createdAt));
-
-      for (final event in events) {
-        logger.fine('event.type: ${event.type}');
-        final messageText = event.message?.text;
-        if (messageText != null) {
-          logger.fine('event.message.text: $messageText');
-        }
-        handleEvent(event);
+  Future<void> sync({List<String>? cids, DateTime? lastSyncAt}) {
+    return synchronized(() async {
+      final channels = cids ?? await _chatPersistenceClient?.getChannelCids();
+      if (channels == null || channels.isEmpty) {
+        return;
       }
 
-      final now = DateTime.now();
-      _lastSyncedAt = now;
-      _chatPersistenceClient?.updateLastSyncAt(now);
-    } catch (e, stk) {
-      logger.severe('Error during sync', e, stk);
-    }
+      final syncAt =
+          lastSyncAt ?? await _chatPersistenceClient?.getLastSyncAt();
+      if (syncAt == null) {
+        return;
+      }
+
+      try {
+        final res = await _chatApi.general.sync(channels, syncAt);
+        final events = res.events
+          ..sort((a, b) => a.createdAt.compareTo(b.createdAt));
+
+        for (final event in events) {
+          logger.fine('event.type: ${event.type}');
+          final messageText = event.message?.text;
+          if (messageText != null) {
+            logger.fine('event.message.text: $messageText');
+          }
+          handleEvent(event);
+        }
+
+        final now = DateTime.now();
+        _lastSyncedAt = now;
+        _chatPersistenceClient?.updateLastSyncAt(now);
+      } catch (e, stk) {
+        logger.severe('Error during sync', e, stk);
+      }
+    });
   }
 
   final _queryChannelsStreams = <String, Future<List<Channel>>>{};
diff --git a/packages/stream_chat/pubspec.yaml b/packages/stream_chat/pubspec.yaml
index f0bbc763..61c1ff97 100644
--- a/packages/stream_chat/pubspec.yaml
+++ b/packages/stream_chat/pubspec.yaml
@@ -22,6 +22,7 @@ dependencies:
   mime: ^1.0.4
   rate_limiter: ^1.0.0
   rxdart: ^0.27.7
+  synchronized: ^3.0.0
   uuid: ^3.0.7
   web_socket_channel: ^2.3.0