diff --git a/CHANGELOG.md b/CHANGELOG.md
index ffb720c..0148891 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 3.0.0-beta.4
+
+**Bug fix:**
+* [#394](https://github.com/rikulo/socket.io-client-dart/issues/394) Incorrect argument matching in notifyOutgoingListeners
+
 ## 3.0.0-beta.3
 
 **Bug fix:**
diff --git a/lib/src/socket.dart b/lib/src/socket.dart
index 1f21ec0..c6e865d 100644
--- a/lib/src/socket.dart
+++ b/lib/src/socket.dart
@@ -319,7 +319,7 @@ class Socket extends EventEmitter {
     if (_anyOutgoingListeners.isNotEmpty) {
       final listeners = List.from(_anyOutgoingListeners);
       for (final listener in listeners) {
-        Function.apply(listener, [packet['data']]);
+        Function.apply(listener, packet['data']);
       }
     }
   }
diff --git a/pubspec.yaml b/pubspec.yaml
index 2bfefed..ba3c790 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: socket_io_client
 description: Dartlang port of socket.io-client for web, flutter, dartvm to use
-version: 3.0.0-beta.3
+version: 3.0.0-beta.4
 homepage: https://www.zkoss.org
 repository: https://github.com/rikulo/socket.io-client-dart
 issue_tracker: https://github.com/rikulo/socket.io-client-dart/issues
diff --git a/test/io_client.dart b/test/io_client.dart
index 935b6fa..d89e4fe 100644
--- a/test/io_client.dart
+++ b/test/io_client.dart
@@ -13,6 +13,9 @@ void main() {
 
   // socket.connect();
 
+  // Test for #394
+  socket.onAnyOutgoing((event, data) => print('outgoing: $event, data: $data'));
+
   socket.onConnect((_) {
     socket.emit('toServer', 'init');