diff --git a/templates/swift/Sources/WebSockets/WebSocketClient.swift.twig b/templates/swift/Sources/WebSockets/WebSocketClient.swift.twig
index 72322b784..e28502e6b 100644
--- a/templates/swift/Sources/WebSockets/WebSocketClient.swift.twig
+++ b/templates/swift/Sources/WebSockets/WebSocketClient.swift.twig
@@ -297,7 +297,13 @@ public class WebSocketClient {
             self.channel = channel
         }
 
-        return channel.pipeline.addHandler(handler)
+        return channel.pipeline.addHandler(handler).map {
+            if let delegate = self.delegate {
+                delegate.onOpen(channel: channel)
+            } else {
+                self.onOpen(channel)
+            }
+        }
     }
 
     // MARK: - Close connection