1 files changed, 27 insertions, 0 deletions
diff --git a/src/test/ui/type-alias-impl-trait/issue-53598.rs b/src/test/ui/type-alias-impl-trait/issue-53598.rs
new file mode 100644
index 000000000..9c1cbf926
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/issue-53598.rs
@@ -0,0 +1,27 @@
+#![feature(type_alias_impl_trait)]
+
+use std::fmt::Debug;
+
+pub trait Foo {
+    type Item: Debug;
+
+    fn foo<T: Debug>(_: T) -> Self::Item;
+}
+
+#[derive(Debug)]
+pub struct S<T>(std::marker::PhantomData<T>);
+
+pub struct S2;
+
+impl Foo for S2 {
+    type Item = impl Debug;
+
+    fn foo<T: Debug>(_: T) -> Self::Item {
+        S::<T>(Default::default())
+        //~^ Error type parameter `T` is part of concrete type but not used in parameter list for the `impl Trait` type alias
+    }
+}
+
+fn main() {
+    S2::foo(123);
+}