diff --git a/yesod-websockets/Yesod/WebSockets.hs b/yesod-websockets/Yesod/WebSockets.hs
index 9d68ee1e..8046f875 100644
--- a/yesod-websockets/Yesod/WebSockets.hs
+++ b/yesod-websockets/Yesod/WebSockets.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE CPP                   #-}
 {-# LANGUAGE FlexibleContexts      #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE ScopedTypeVariables   #-}
 module Yesod.WebSockets
     ( -- * Core API
       WebSocketsT