diff --git a/src/Utils/TH.hs b/src/Utils/TH.hs
index 40669cc2f..d2d9d515f 100644
--- a/src/Utils/TH.hs
+++ b/src/Utils/TH.hs
@@ -111,6 +111,9 @@ afterN n = do
 deriveShowWith :: (String -> String) -> Name -> Q [Dec]
 deriveShowWith = deriveSimpleWith ''Show 'show
 
+unitTypeOut :: () -> ()
+unitTypeOut = id
+
 deriveSimpleWith ::  Name -> Name -> (String -> String) -> Name -> Q [Dec]
 deriveSimpleWith cls fun strOp ty = do
     (TyConI tyCon)  <- reify ty
@@ -125,7 +128,7 @@ deriveSimpleWith cls fun strOp ty = do
 
     genClause :: Con -> Q Clause
     genClause (NormalC name []) =
-      let pats = [ConP name []]
+      let pats = [ConP name [] []]
           body = NormalB $ LitE $ StringL $ strOp $ nameBase name
       in return $ Clause pats body []
     genClause _ = fail "deriveShowTheme: constructors not allowed to have arguments"