diff --git a/lib/dart/lib/src/transport/t_socket.dart b/lib/dart/lib/src/transport/t_socket.dart
index 74618b6..b2eb6b6 100644
--- a/lib/dart/lib/src/transport/t_socket.dart
+++ b/lib/dart/lib/src/transport/t_socket.dart
@@ -22,7 +22,7 @@
 abstract class TSocket {
   Stream<TSocketState> get onState;
 
-  Stream<String> get onError;
+  Stream<Object> get onError;
 
   Stream<Uint8List> get onMessage;