diff --git a/src/test/run-pass/unique-fn-arg-mut.rs b/src/test/run-pass/unique-fn-arg-mut.rs
new file mode 100644
index 000000000000..7743b4b44a4e
--- /dev/null
+++ b/src/test/run-pass/unique-fn-arg-mut.rs
@@ -0,0 +1,9 @@
+fn f(&i: ~int) {
+    i = ~200;
+}
+
+fn main() {
+    let i = ~100;
+    f(i);
+    assert *i == 200;
+}
\ No newline at end of file