diff --git a/yesod-core/Yesod/Core/Internal/Run.hs b/yesod-core/Yesod/Core/Internal/Run.hs
index cb72b881..9bd1e9c0 100644
--- a/yesod-core/Yesod/Core/Internal/Run.hs
+++ b/yesod-core/Yesod/Core/Internal/Run.hs
@@ -10,7 +10,7 @@ module Yesod.Core.Internal.Run where
 
 
 #if __GLASGOW_HASKELL__ < 710
-import           Data.Monoid                  (mempty)
+import           Data.Monoid                  (Monoid, mempty)
 #endif
 import Yesod.Core.Internal.Response
 import           Blaze.ByteString.Builder     (toByteString)