diff --git a/rtgui/saveasdlg.h b/rtgui/saveasdlg.h
index 9cafe7ded..bb4615d94 100644
--- a/rtgui/saveasdlg.h
+++ b/rtgui/saveasdlg.h
@@ -17,6 +17,7 @@
  *  along with RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
  */
 #ifndef _SAVEASDLG_
+#define _SAVEASDLG
 
 #include <gtkmm.h>
 #include "adjuster.h"