diff --git a/aeson-flowtyped.cabal b/aeson-flowtyped.cabal
--- a/aeson-flowtyped.cabal
+++ b/aeson-flowtyped.cabal
@@ -1,5 +1,5 @@
 name:           aeson-flowtyped
-version:        0.12.1
+version:        0.12.2
 synopsis:       Create Flow or TypeScript type definitions from Haskell data types.
 description:    Create Flow or TypeScript type definitions from Haskell data types.
 category:       Web
diff --git a/src/Data/Aeson/Flow.hs b/src/Data/Aeson/Flow.hs
--- a/src/Data/Aeson/Flow.hs
+++ b/src/Data/Aeson/Flow.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE AllowAmbiguousTypes       #-}
 {-# LANGUAGE ConstraintKinds           #-}
 {-# LANGUAGE CPP                       #-}
 {-# LANGUAGE DataKinds                 #-}
@@ -586,9 +587,9 @@
   }
 
 data Export where
-  Export :: (FlowCallable a) => Proxy a -> Export
+  Export :: FlowCallable a => Proxy a -> Export
 
-export :: forall a. (FlowCallable a) => Export
+export :: forall a. FlowCallable a => Export
 export = Export (Proxy :: Proxy a)
 
 instance Eq Export where