1 files changed, 8 insertions, 0 deletions
diff --git a/tests/ui/on-unimplemented/issue-104140.rs b/tests/ui/on-unimplemented/issue-104140.rs
new file mode 100644
index 00000000000..ade3f727004
--- /dev/null
+++ b/tests/ui/on-unimplemented/issue-104140.rs
@@ -0,0 +1,8 @@
+#![feature(rustc_attrs)]
+
+trait Foo {}
+
+#[rustc_on_unimplemented] //~ ERROR malformed `rustc_on_unimplemented` attribute input
+impl Foo for u32 {}
+
+fn main() {}