1 files changed, 1 insertions, 1 deletions

diff --git a/Pipes/Text.hs b/Pipes/Text.hs
index 7a10f1e..e41689c 100644
--- a/Pipes/Text.hs
+++ b/Pipes/Text.hs
@@ -790,4 +790,4 @@ intercalate p0 = go0
 -}
 
 
-type Lens' a b =  Functor f => (b -> f b) -> (a -> f a)
+type Lens' a b =  forall f . Functor f => (b -> f b) -> (a -> f a)