diff --git a/src/plugins/android/avdmanageroutputparser.h b/src/plugins/android/avdmanageroutputparser.h
index ac65fce02bb..b3a74f8fc8e 100644
--- a/src/plugins/android/avdmanageroutputparser.h
+++ b/src/plugins/android/avdmanageroutputparser.h
@@ -1,6 +1,8 @@
 // Copyright (C) 2021 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
+#pragma once
+
 #include "androiddeviceinfo.h"
 
 namespace Android {
diff --git a/src/plugins/cmakeprojectmanager/projecttreehelper.h b/src/plugins/cmakeprojectmanager/projecttreehelper.h
index aa655492d4a..08707360ed4 100644
--- a/src/plugins/cmakeprojectmanager/projecttreehelper.h
+++ b/src/plugins/cmakeprojectmanager/projecttreehelper.h
@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
+#pragma once
+
 #include "cmakeprojectnodes.h"
 
 #include <utils/filepath.h>
diff --git a/src/plugins/python/pythonwizardpage.h b/src/plugins/python/pythonwizardpage.h
index 6cf8a130c59..9691e767524 100644
--- a/src/plugins/python/pythonwizardpage.h
+++ b/src/plugins/python/pythonwizardpage.h
@@ -1,6 +1,8 @@
 // Copyright (C) 2022 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
+#pragma once
+
 #include <projectexplorer/jsonwizard/jsonwizard.h>
 #include <projectexplorer/jsonwizard/jsonwizardpagefactory.h>
 #include <projectexplorer/runconfigurationaspects.h>
diff --git a/src/plugins/silversearcher/silversearcherparser_test.h b/src/plugins/silversearcher/silversearcherparser_test.h
index 6d85cd21981..4278fb95159 100644
--- a/src/plugins/silversearcher/silversearcherparser_test.h
+++ b/src/plugins/silversearcher/silversearcherparser_test.h
@@ -1,6 +1,8 @@
 // Copyright (C) 2017 Przemyslaw Gorszkowski <pgorszkowski@gmail.com>.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
+#pragma once
+
 #include <QObject>
 
 namespace SilverSearcher {
diff --git a/src/tools/buildoutputparser/outputprocessor.h b/src/tools/buildoutputparser/outputprocessor.h
index 4a34a5203e5..d0ca1616fb8 100644
--- a/src/tools/buildoutputparser/outputprocessor.h
+++ b/src/tools/buildoutputparser/outputprocessor.h
@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
+#pragma once
+
 #include <QObject>
 
 QT_BEGIN_NAMESPACE