1 files changed, 13 insertions, 0 deletions
diff --git a/tests/ui/closures/closure-immutable-outer-variable.fixed b/tests/ui/closures/closure-immutable-outer-variable.fixed
new file mode 100644
index 00000000000..1b0feede34e
--- /dev/null
+++ b/tests/ui/closures/closure-immutable-outer-variable.fixed
@@ -0,0 +1,13 @@
+// run-rustfix
+
+// Point at the captured immutable outer variable
+
+fn foo(mut f: Box<dyn FnMut()>) {
+    f();
+}
+
+fn main() {
+    let mut y = true;
+    foo(Box::new(move || y = !y) as Box<_>);
+    //~^ ERROR cannot assign to `y`, as it is not declared as mutable
+}