diff --git a/src/ap.c b/src/ap.c
index af6a1709..416e1104 100644
--- a/src/ap.c
+++ b/src/ap.c
@@ -24,6 +24,7 @@
 #include <config.h>
 #endif
 
+#define _GNU_SOURCE
 #include <errno.h>
 #include <linux/if_ether.h>
 #include <netinet/in.h>