diff --git a/Megadeth/Prim.hs b/Megadeth/Prim.hs
index ad1782c..2f39336 100644
--- a/bundled/megadeth/Megadeth/Prim.hs
+++ b/bundled/megadeth/Megadeth/Prim.hs
@@ -82,3 +82,3 @@ simpleConView tyName c =
   ForallC _ _ innerCon -> simpleConView tyName innerCon
-
+  _ -> error $ "simpleConView: failed on " ++ show c