diff --git a/src/plugins/clangformat/clangformatconfigwidget.h b/src/plugins/clangformat/clangformatconfigwidget.h
index 39ab5e0c5e0..3e8334dea91 100644
--- a/src/plugins/clangformat/clangformatconfigwidget.h
+++ b/src/plugins/clangformat/clangformatconfigwidget.h
@@ -3,6 +3,12 @@
 
 #pragma once
 
+#include <QtGlobal>
+
+QT_BEGIN_NAMESPACE
+class QWidget;
+QT_END_NAMESPACE
+
 namespace CppEditor { class CppCodeStyleWidget; }
 namespace TextEditor { class ICodeStylePreferences; }
 namespace ProjectExplorer { class Project; }