diff --git a/src/func/tests.rs b/src/func/tests.rs
index 66d57ba..0ce3d81 100644
--- a/src/func/tests.rs
+++ b/src/func/tests.rs
@@ -320,7 +320,7 @@ pub fn fmap_can_be_expressed_via_bind<
 
 pub fn void_can_be_exressed_via_replace<
     'a,
-    T: Monad<'a> + Eqr<'a>,
+    T: Functor<'a> + Eqr<'a>,
     A: 'a + Send + Debug + PartialEq,
 >(
     fa0: impl Fn() -> T::F<A>,