diff --git a/src/Data/IsTy.hs b/src/Data/IsTy.hs
--- a/src/Data/IsTy.hs
+++ b/src/Data/IsTy.hs
@@ -38,4 +38,4 @@
   type IsTy2Constraint f u v :: Constraint
   type IsTy2Constraint f u v = Yes2 f u v
   tyEq2 :: (IsTy2Constraint f a b, IsTy2Constraint f c d) =>
-           f a b -> f c d -> Maybe (a :=: c, b :=: d)
+           f a b -> f c d -> Maybe ((a,b) :=: (c,d))
diff --git a/ty.cabal b/ty.cabal
--- a/ty.cabal
+++ b/ty.cabal
@@ -1,5 +1,5 @@
 Name:                ty
-Version:             0.1.3
+Version:             0.1.4
 Synopsis:            Typed type representations and equality proofs
 Category:            Data
 Cabal-Version:       >= 1.6