diff --git a/freeglut/freeglut/config.h.in b/freeglut/freeglut/config.h.in
index 0db8c4f..f38897a 100644
--- a/freeglut/freeglut/config.h.in
+++ b/freeglut/freeglut/config.h.in
@@ -15,4 +15,4 @@
 #cmakedefine NEED_XPARSEGEOMETRY_IMPL
 #cmakedefine HAVE_STDINT_H
 #cmakedefine HAVE_INTTYPES_H
-#define HAVE_ULONG_LONG ${HAVE_ULONG_LONG}
+#cmakedefine HAVE_ULONG_LONG