1 files changed, 2 insertions, 1 deletions
diff --git a/users/grfn/xanthous/src/Data/Aeson/Generic/DerivingVia.hs b/users/grfn/xanthous/src/Data/Aeson/Generic/DerivingVia.hs
index 34f2a94038..e89fcd6211 100644
--- a/users/grfn/xanthous/src/Data/Aeson/Generic/DerivingVia.hs
+++ b/users/grfn/xanthous/src/Data/Aeson/Generic/DerivingVia.hs
@@ -89,7 +89,8 @@ type TagSingleConstructors  = 'TagSingleConstructors
 class Demotable (a :: k) where
   demote :: proxy a -> Demoted k
 
-type family All (p :: Type -> Constraint) (xs :: [k]) :: Constraint where
+type All :: (Type -> Constraint) -> [Type] -> Constraint
+type family All p xs where
   All p '[] = ()
   All p (x ': xs) = (p x, All p xs)