diff --git a/src/libmdb/fakeglib.c b/src/libmdb/fakeglib.c
index e6b67d6..244647e 100644
--- a/src/libmdb/fakeglib.c
+++ b/src/libmdb/fakeglib.c
@@ -18,7 +18,6 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#define _GNU_SOURCE
 #include "mdbfakeglib.h"
 
 #include <stddef.h>