diff --git a/src/Config.h.in b/src/Config.h.in
index 2b03e76c5..79e5bad39 100644
--- a/src/Config.h.in
+++ b/src/Config.h.in
@@ -7,6 +7,7 @@
 #define CMAKE_INSTALL_FULL_LIBEXECDIR "${CMAKE_INSTALL_FULL_LIBEXECDIR}"
 
 
+#cmakedefine MOUNTAIN_LION
 #cmakedefine LION
 #cmakedefine SNOW_LEOPARD
 #cmakedefine LEOPARD