1 files changed, 9 insertions, 0 deletions

diff --git a/tests/ui/issues/issue-40000.rs b/tests/ui/issues/issue-40000.rs
new file mode 100644
index 00000000000..a6e05e7ba02
--- /dev/null
+++ b/tests/ui/issues/issue-40000.rs
@@ -0,0 +1,9 @@
+fn main() {
+    let bar: fn(&mut u32) = |_| {};
+
+    fn foo(x: Box<dyn Fn(&i32)>) {}
+    let bar = Box::new(|x: &i32| {}) as Box<dyn Fn(_)>;
+    foo(bar);
+    //~^ ERROR mismatched types
+    //~| ERROR mismatched types
+}