1 files changed, 18 insertions, 0 deletions
diff --git a/src/test/ui/specialization/min_specialization/specialization_super_trait.rs b/src/test/ui/specialization/min_specialization/specialization_super_trait.rs
new file mode 100644
index 000000000..145f376ed
--- /dev/null
+++ b/src/test/ui/specialization/min_specialization/specialization_super_trait.rs
@@ -0,0 +1,18 @@
+// Test that supertraits can't be assumed in impls of
+// `rustc_specialization_trait`, as such impls would
+// allow specializing on the supertrait.
+
+#![feature(min_specialization)]
+#![feature(rustc_attrs)]
+
+#[rustc_specialization_trait]
+trait SpecMarker: Default {
+    fn f();
+}
+
+impl<T: Default> SpecMarker for T {
+    //~^ ERROR cannot specialize
+    fn f() {}
+}
+
+fn main() {}