diff --git a/src/flow/binary.rs b/src/flow/binary.rs
index 9e5ef58..ec6a11f 100644
--- a/src/flow/binary.rs
+++ b/src/flow/binary.rs
@@ -14,7 +14,7 @@ pub type Split<'a, BT> = (
 );
 pub type KeySplit<'a, BT> = (<BT as BinaryTrees<'a>>::Tree, <BT as BinaryTrees<'a>>::Tree);
 
-pub type BTWrap<'a, BT, A> = Wrap<'a, A, <BT as FunctorContext<'a>>::T>;
+pub type BTWrap<'a, BT, A> = WrapC<'a, A, BT>;
 
 pub trait BinaryTrees<'a>: FunctorContext<'a, T = Self::_Tm> + Clone {
     type Node: 'a;