Fix Trac #3423: missed instantiation for newtype-derived instances

[ghc-hetmet.git] / compiler / typecheck / TcMType.lhs

diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs
index 030a7f6..94c2d25 100644 (file)
--- a/compiler/typecheck/TcMType.lhs
+++ b/compiler/typecheck/TcMType.lhs
@@ -415,7 +415,7 @@ occurCheckErr ty containingTy
 newCoVars :: [(TcType,TcType)] -> TcM [CoVar]
 newCoVars spec
   = do { us <- newUniqueSupply 
-       ; return [ mkCoVar (mkSysTvName uniq (fsLit "co"))
+       ; return [ mkCoVar (mkSysTvName uniq (fsLit "co_kv"))
                           (mkCoKind ty1 ty2)
                 | ((ty1,ty2), uniq) <- spec `zip` uniqsFromSupply us] }