diff --git a/tests/manual/debugger/simple/simple_test_app.cpp b/tests/manual/debugger/simple/simple_test_app.cpp
index ee6ce38d866c5f33a2b5953900f772e5e8ab9faa..17a528aae92175bfa4db9b3c37d8b79835ad9400 100644
--- a/tests/manual/debugger/simple/simple_test_app.cpp
+++ b/tests/manual/debugger/simple/simple_test_app.cpp
@@ -1208,8 +1208,9 @@ namespace qobject {
 
     #if USE_PRIVATE
 
-    struct DerivedObjectPrivate : public QObjectPrivate
+    class DerivedObjectPrivate : public QObjectPrivate
     {
+    public:
         DerivedObjectPrivate() {
             m_extraX = 43;
             m_extraY.append("xxx");