2 files changed, 22 insertions, 0 deletions
diff --git a/tests/ui/async-await/return-type-notation/supertrait-bound.rs b/tests/ui/async-await/return-type-notation/supertrait-bound.rs
new file mode 100644
index 00000000000..19bcfe3046b
--- /dev/null
+++ b/tests/ui/async-await/return-type-notation/supertrait-bound.rs
@@ -0,0 +1,11 @@
+// check-pass
+
+#![feature(return_position_impl_trait_in_trait, return_type_notation)]
+//~^ WARN the feature `return_type_notation` is incomplete and may not be safe to use
+
+trait IntFactory {
+    fn stream(&self) -> impl Iterator<Item = i32>;
+}
+trait SendIntFactory: IntFactory<stream(): Send> + Send {}
+
+fn main() {}
diff --git a/tests/ui/async-await/return-type-notation/supertrait-bound.stderr b/tests/ui/async-await/return-type-notation/supertrait-bound.stderr
new file mode 100644
index 00000000000..c8cec4946b4
--- /dev/null
+++ b/tests/ui/async-await/return-type-notation/supertrait-bound.stderr
@@ -0,0 +1,11 @@
+warning: the feature `return_type_notation` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/supertrait-bound.rs:3:49
+   |
+LL | #![feature(return_position_impl_trait_in_trait, return_type_notation)]
+   |                                                 ^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #109417 <https://github.com/rust-lang/rust/issues/109417> for more information
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+