diff --git a/src/gui/kernel/qplatformdialoghelper.cpp b/src/gui/kernel/qplatformdialoghelper.cpp
index 20dc716d89..f69efe0935 100644
--- a/src/gui/kernel/qplatformdialoghelper.cpp
+++ b/src/gui/kernel/qplatformdialoghelper.cpp
@@ -119,6 +119,8 @@ static const int buttonRoleLayouts[2][5][14] =
 
 QPlatformDialogHelper::QPlatformDialogHelper()
 {
+    qRegisterMetaType<StandardButton>();
+    qRegisterMetaType<ButtonRole>();
 }
 
 QPlatformDialogHelper::~QPlatformDialogHelper()
diff --git a/src/gui/kernel/qplatformdialoghelper.h b/src/gui/kernel/qplatformdialoghelper.h
index ec88770862..936dbdfa89 100644
--- a/src/gui/kernel/qplatformdialoghelper.h
+++ b/src/gui/kernel/qplatformdialoghelper.h
@@ -160,6 +160,11 @@ Q_SIGNALS:
     void reject();
 };
 
+QT_END_NAMESPACE
+Q_DECLARE_METATYPE(QPlatformDialogHelper::StandardButton)
+Q_DECLARE_METATYPE(QPlatformDialogHelper::ButtonRole)
+QT_BEGIN_NAMESPACE
+
 class Q_GUI_EXPORT QColorDialogOptions
 {
 public: