diff --git a/tests/target/fn.rs b/tests/target/fn.rs
index bc05efa5351..f48e8eaddc6 100644
--- a/tests/target/fn.rs
+++ b/tests/target/fn.rs
@@ -75,6 +75,10 @@ impl Foo {
     }
 }
 
+fn homura<T: Deref<Target = i32>>(_: T) {
+
+}
+
 fn main() {
     let _ = function(move || 5);
     let _ = move || 42;