diff --git a/websocket-sharp/Ext.cs b/websocket-sharp/Ext.cs
index 4713ac41..5e42b235 100644
--- a/websocket-sharp/Ext.cs
+++ b/websocket-sharp/Ext.cs
@@ -595,6 +595,13 @@ namespace WebSocketSharp
       return opcode == Opcode.Text || opcode == Opcode.Binary;
     }
 
+    internal static bool IsHttpMethod (this string value, Version version)
+    {
+      return version == HttpVersion.Version10
+             ? value.isHttpMethod10 ()
+             : value.isHttpMethod ();
+    }
+
     internal static bool IsPortNumber (this int value)
     {
       return value > 0 && value < 65536;