diff --git a/websocket-sharp/Net/HttpUtility.cs b/websocket-sharp/Net/HttpUtility.cs
index 24d7f0f2..53919a8d 100644
--- a/websocket-sharp/Net/HttpUtility.cs
+++ b/websocket-sharp/Net/HttpUtility.cs
@@ -529,6 +529,20 @@ namespace WebSocketSharp.Net
       output.WriteByte ((byte) num);
     }
 
+    private static void urlDecodeUnicode (
+      byte[] bytes, int offset, Stream output
+    )
+    {
+      var num = getNumber (bytes, offset + 2, 4);
+      if (num == -1) {
+        output.Write (bytes, offset, 6);
+        return;
+      }
+
+      var decoded = Encoding.Unicode.GetBytes (new[] { (char) num });
+      output.Write (decoded, 0, decoded.Length);
+    }
+
     private static void urlEncode (byte b, Stream output)
     {
       if (b > 31 && b < 127) {