diff --git a/example/example5.cpp b/example/example5.cpp
index c601ed7..f6de5ba 100644
--- a/example/example5.cpp
+++ b/example/example5.cpp
@@ -65,7 +65,7 @@
 }
 
 int test_callback2(py::object func) {
-    py::object result = func.call("Hello", true, 5);
+    py::object result = func.call("Hello", 'x', true, 5);
     return result.cast<int>();
 }