diff --git a/src/rstd/collections/stack.rs b/src/rstd/collections/stack.rs
index 3512786..7d1be93 100644
--- a/src/rstd/collections/stack.rs
+++ b/src/rstd/collections/stack.rs
@@ -142,7 +142,7 @@ impl<F> StackNodeFactory<F> {
 
 impl<'a, Ctx: Context<'a>, F: Factory<'a, Ctx>> FactoryBase<'a, Ctx> for StackNodeFactory<F>
 where
-    F::Mtbl: StackCompatible<'a, Ctx, _Fctr = F>,
+    F::Mtbl: StackCompatible<'a, Ctx>,
 {
     type Mtbl = StackNode<'a, Ctx, F::Mtbl>;