diff --git a/websocket-sharp/Net/WebHeaderCollection.cs b/websocket-sharp/Net/WebHeaderCollection.cs
index fdf4827b..5b85fc7a 100644
--- a/websocket-sharp/Net/WebHeaderCollection.cs
+++ b/websocket-sharp/Net/WebHeaderCollection.cs
@@ -1670,7 +1670,7 @@ namespace WebSocketSharp.Net
       var name = getHeaderName (key);
 
       checkRestricted (name, HttpHeaderType.Response);
-      checkAllowed (true);
+      checkAllowed (HttpHeaderType.Response);
       base.Remove (name);
     }