diff --git a/rtgui/config.h.in b/rtgui/config.h.in
index d5f46316c..cab481278 100644
--- a/rtgui/config.h.in
+++ b/rtgui/config.h.in
@@ -20,6 +20,7 @@
 #ifndef __CONFIG_H__
 #define __CONFIG_H__
 
+#cmakedefine BUILD_BUNDLE
 #define DATA_SEARCH_PATH "${DATADIR}"
 #define DOC_SEARCH_PATH "${DOCDIR}"
 #define CREDITS_SEARCH_PATH "${CREDITSDIR}"