diff --git a/src/plugins/coreplugin/dialogs/filepropertiesdialog.h b/src/plugins/coreplugin/dialogs/filepropertiesdialog.h
index 3459b61e433..906e26aa237 100644
--- a/src/plugins/coreplugin/dialogs/filepropertiesdialog.h
+++ b/src/plugins/coreplugin/dialogs/filepropertiesdialog.h
@@ -30,9 +30,11 @@
 #include <QDialog>
 #include <QFile>
 
+QT_BEGIN_NAMESPACE
 namespace Ui {
 class FilePropertiesDialog;
 }
+QT_END_NAMESPACE
 
 class FilePropertiesDialog : public QDialog
 {
diff --git a/src/plugins/serialterminal/serialterminalsettings.h b/src/plugins/serialterminal/serialterminalsettings.h
index 250eec48b71..06a9cb0cec7 100644
--- a/src/plugins/serialterminal/serialterminalsettings.h
+++ b/src/plugins/serialterminal/serialterminalsettings.h
@@ -31,7 +31,9 @@
 #include <QString>
 #include <QVector>
 
+QT_BEGIN_NAMESPACE
 class QSettings;
+QT_END_NAMESPACE
 
 namespace SerialTerminal {
 namespace Internal {