diff --git a/src/Constraints.hs b/src/Constraints.hs
index 851b1234..a56ea57d 100644
--- a/src/Constraints.hs
+++ b/src/Constraints.hs
@@ -177,6 +177,8 @@ solveOneInternal mappings constraint =
             Left err -> Left err
             Right ok -> foldM (\m (aa, bb) -> solveOneInternal m (Constraint aa bb i1 i2 ctx ord)) ok (zip args [b, ltB])
     -- Else
+    Constraint _ CTy _ _ _ _ -> Right mappings
+    Constraint CTy _ _ _ _ _ -> Right mappings
     Constraint aTy bTy _ _ _ _ ->
       if aTy == bTy
         then Right mappings
diff --git a/src/Types.hs b/src/Types.hs
index 8c82322f..319d2389 100644
--- a/src/Types.hs
+++ b/src/Types.hs
@@ -291,6 +291,8 @@ areUnifiable (FuncTy argTysA retTyA ltA) (FuncTy argTysB retTyB ltB)
         ltBool = areUnifiable ltA ltB
      in all (== True) (ltBool : retBool : argBools)
 areUnifiable FuncTy {} _ = False
+areUnifiable CTy _ = True
+areUnifiable _ CTy = True
 areUnifiable a b
   | a == b = True
   | otherwise = False