1 files changed, 9 insertions, 0 deletions
diff --git a/tests/ui/lint/force-warn/deny-by-default-lint.rs b/tests/ui/lint/force-warn/deny-by-default-lint.rs
new file mode 100644
index 00000000000..c2e9377e908
--- /dev/null
+++ b/tests/ui/lint/force-warn/deny-by-default-lint.rs
@@ -0,0 +1,9 @@
+// --force-warn $LINT causes $LINT (which is deny-by-default) to warn
+// compile-flags: --force-warn mutable_transmutes
+// check-pass
+
+fn main() {
+    unsafe {
+        let y = std::mem::transmute::<&i32, &mut i32>(&5); //~WARN: undefined behavior
+    }
+}