diff --git a/extras/libmemif/src/main.c b/extras/libmemif/src/main.c
index 6048e4e..d5a4319 100644
--- a/extras/libmemif/src/main.c
+++ b/extras/libmemif/src/main.c
@@ -15,6 +15,7 @@
  *------------------------------------------------------------------
  */
 
+#define _GNU_SOURCE
 #include <stdint.h>
 #include <net/if.h>
 #include <sys/types.h>