diff --git a/src/plugins/qmldesigner/qmldesignerextension/timelineeditor/easingcurvedialog.h b/src/plugins/qmldesigner/qmldesignerextension/timelineeditor/easingcurvedialog.h
index d4a171af377..a8c026989c2 100644
--- a/src/plugins/qmldesigner/qmldesignerextension/timelineeditor/easingcurvedialog.h
+++ b/src/plugins/qmldesigner/qmldesignerextension/timelineeditor/easingcurvedialog.h
@@ -30,9 +30,11 @@
 
 #include <modelnode.h>
 
+QT_BEGIN_NAMESPACE
 class QLabel;
 class QPlainTextEdit;
 class QHBoxLayout;
+QT_END_NAMESPACE
 
 namespace QmlDesigner {