diff --git a/tests/cxx_string.rs b/tests/cxx_string.rs
index d651408ea..878be942b 100644
--- a/tests/cxx_string.rs
+++ b/tests/cxx_string.rs
@@ -21,6 +21,13 @@ fn test_async_cxx_string() {
     assert_send(f());
 }
 
+#[test]
+fn test_display() {
+    let_cxx_string!(s = b"w\"x\'y\xF1\x80\xF1\x80z");
+
+    assert_eq!(format!("{}", s), "w\"x'y\u{fffd}\u{fffd}z");
+}
+
 #[test]
 fn test_debug() {
     let_cxx_string!(s = b"w\"x\'y\xF1\x80z");