diff --git a/src/plugins/qmldesigner/components/propertyeditor/declarativewidgetview.h b/src/plugins/qmldesigner/components/propertyeditor/declarativewidgetview.h
index 7a808581c36026cc50a07f0844347c0364c48c12..c36fe4a74d8cb1e7b15c8faec57d056c55e48fcb 100644
--- a/src/plugins/qmldesigner/components/propertyeditor/declarativewidgetview.h
+++ b/src/plugins/qmldesigner/components/propertyeditor/declarativewidgetview.h
@@ -4,9 +4,11 @@
 #include <QWidget>
 #include <QUrl>
 
+QT_BEGIN_NAMESPACE
 class QDeclarativeEngine;
 class QDeclarativeContext;
 class QDeclarativeError;
+QT_END_NAMESPACE
 
 namespace QmlDesigner {