diff --git a/SingleUserInput.hpp b/SingleUserInput.hpp
index b0ec8e6..7d21e5b 100644
--- a/SingleUserInput.hpp
+++ b/SingleUserInput.hpp
@@ -1,3 +1,8 @@
+/**
+ * @brief stores a single user input (printable and function keys)
+ * @author Christian Burger (christian@krikkel.de)
+ */
+
 #ifndef F0E30ED4_3883_40D6_A6EE_08BA4DF9E92E
 #define F0E30ED4_3883_40D6_A6EE_08BA4DF9E92E
 
diff --git a/Window.hpp b/Window.hpp
index 243d063..6aaa542 100644
--- a/Window.hpp
+++ b/Window.hpp
@@ -3,6 +3,9 @@
  * @author Christian Burger (christian@krikkel.de)
  */
 
+#ifndef __WINDOW_H__
+#define __WINDOW_H__
+
 #include "SingleUserInput.hpp"
 
 #include <cursesw.h>
@@ -84,4 +87,5 @@ namespace krikkel::NCursesPtyWindow
             static int staticHandlerPopLine(int cols, VTermScreenCell *cells, void *user);
             static void staticHandlerOutput(const char *s, size_t len, void *user);
     };
-}
\ No newline at end of file
+}
+#endif // __WINDOW_H__
\ No newline at end of file