diff --git a/src/main/java/com/corundumstudio/socketio/handler/EncoderHandler.java b/src/main/java/com/corundumstudio/socketio/handler/EncoderHandler.java
index 0637337..8832dde 100644
--- a/src/main/java/com/corundumstudio/socketio/handler/EncoderHandler.java
+++ b/src/main/java/com/corundumstudio/socketio/handler/EncoderHandler.java
@@ -177,7 +177,6 @@ public class EncoderHandler extends ChannelOutboundHandlerAdapter {
                 HttpHeaders.addHeader(res, ACCESS_CONTROL_ALLOW_CREDENTIALS, Boolean.TRUE);
             } else {
                 HttpHeaders.addHeader(res, ACCESS_CONTROL_ALLOW_ORIGIN, "*");
-                HttpHeaders.addHeader(res, ACCESS_CONTROL_ALLOW_CREDENTIALS, Boolean.TRUE);
             }
         }
     }