diff --git a/src/plugins/qmlinspector/startexternalqmldialog.h b/src/plugins/qmlinspector/startexternalqmldialog.h
index b75fa3db880..225fc06f2e7 100644
--- a/src/plugins/qmlinspector/startexternalqmldialog.h
+++ b/src/plugins/qmlinspector/startexternalqmldialog.h
@@ -3,9 +3,11 @@
 
 #include <QDialog>
 
+QT_BEGIN_NAMESPACE
 namespace Ui {
     class StartExternalQmlDialog;
 }
+QT_END_NAMESPACE
 
 namespace Qml {
 namespace Internal {