diff --git a/src/plugins/modeleditor/extpropertiesmview.cpp b/src/plugins/modeleditor/extpropertiesmview.cpp
index e0ac9d1b528..05acb4435b5 100644
--- a/src/plugins/modeleditor/extpropertiesmview.cpp
+++ b/src/plugins/modeleditor/extpropertiesmview.cpp
@@ -35,6 +35,9 @@
 #include <QFileInfo>
 #include <QDir>
 
+namespace ModelEditor {
+namespace Internal {
+
 ExtPropertiesMView::ExtPropertiesMView(qmt::PropertiesView *view)
     : qmt::PropertiesView::MView(view)
 {
@@ -107,3 +110,6 @@ void ExtPropertiesMView::onConfigPathChanged(const QString &path)
     if (modified && m_configPathInfo)
         m_configPathInfo->setText(tr("<font color=red>Model file must be reloaded.</font>"));
 }
+
+} // namespace Interal
+} // namespace ModelEditor
diff --git a/src/plugins/modeleditor/extpropertiesmview.h b/src/plugins/modeleditor/extpropertiesmview.h
index 61fc732377c..1ad45aff819 100644
--- a/src/plugins/modeleditor/extpropertiesmview.h
+++ b/src/plugins/modeleditor/extpropertiesmview.h
@@ -31,6 +31,9 @@
 namespace qmt { class ProjectController; }
 namespace Utils { class PathChooser; }
 
+namespace ModelEditor {
+namespace Internal {
+
 class ExtPropertiesMView : public qmt::PropertiesView::MView
 {
     Q_OBJECT
@@ -52,4 +55,7 @@ private:
     QLabel *m_configPathInfo = 0;
 };
 
+} // namespace Interal
+} // namespace ModelEditor
+
 #endif // EXTPROPERTIESMVIEW_H