Make mkDFunUnfolding more robust

[ghc-hetmet.git] / compiler / iface / TcIface.lhs

diff --git a/compiler/iface/TcIface.lhs b/compiler/iface/TcIface.lhs
index c880a8a..8dccc72 100644 (file)
--- a/compiler/iface/TcIface.lhs
+++ b/compiler/iface/TcIface.lhs
@@ -989,7 +989,7 @@ tcIdDetails _  IfVanillaId = return VanillaId
 tcIdDetails ty (IfDFunId ns)
   = return (DFunId ns (isNewTyCon (classTyCon cls)))
   where
-    (_, cls, _) = tcSplitDFunTy ty
+    (_, _, cls, _) = tcSplitDFunTy ty
 
 tcIdDetails _ (IfRecSelId tc naughty)
   = do { tc' <- tcIfaceTyCon tc