diff --git a/src/qtviewer/MessageLogger.h b/src/qtviewer/MessageLogger.h
index 9b4b7df446..41c6a29a65 100644
--- a/src/qtviewer/MessageLogger.h
+++ b/src/qtviewer/MessageLogger.h
@@ -1,3 +1,6 @@
+#ifndef MESSAGELOGGER_H
+#define MESSAGELOGGER_H
+
 #include <QObject>
 #include <string>
 
@@ -38,3 +41,5 @@ private:
     // Disable copy assignment operator for MessageLogger
     MessageLogger& operator=(const MessageLogger&) = delete;
 };
+
+#endif // MESSAGELOGGER_H
diff --git a/src/qtviewer/MouseHandler.h b/src/qtviewer/MouseHandler.h
index 386e2deb9f..89c3bf6e9f 100644
--- a/src/qtviewer/MouseHandler.h
+++ b/src/qtviewer/MouseHandler.h
@@ -1,3 +1,6 @@
+#ifndef MOUSEHANDLER_H
+#define MOUSEHANDLER_H
+
 #include <osgViewer/Viewer>
 #include <osgGA/TrackballManipulator>
 
@@ -10,7 +13,9 @@ class MouseHandler : public osgGA::TrackballManipulator
         virtual bool handle(
             const osgGA::GUIEventAdapter& ea,
             const osgGA::GUIActionAdapter& aa
-        );
+        ); 
     private:
         osgViewer::Viewer* viewer;
 };
+
+#endif // MOUSEHANDLER_H