diff --git a/Data/Category/Comma.hs b/Data/Category/Comma.hs
--- a/Data/Category/Comma.hs
+++ b/Data/Category/Comma.hs
@@ -21,7 +21,7 @@
 
 data CommaO :: * -> * -> * -> * where
   CommaO :: (Cod t ~ (~>), Cod s ~ (~>))
-    => Obj (Dom t) a -> (t :% a ~> s :% b) -> Obj (Dom s) b -> CommaO t s (a, b)
+    => Obj (Dom t) a -> ((t :% a) ~> (s :% b)) -> Obj (Dom s) b -> CommaO t s (a, b)
     
 data (:/\:) :: * -> * -> * -> * -> * where 
   CommaA :: 
diff --git a/data-category.cabal b/data-category.cabal
--- a/data-category.cabal
+++ b/data-category.cabal
@@ -1,5 +1,5 @@
 name:                data-category
-version:             0.3.0
+version:             0.3.0.1
 synopsis:            Restricted categories
 
 description:         Data-category is a collection of categories, and some categorical constructions on them.