diff --git a/wired/ethdev.c b/wired/ethdev.c
index ed128006..29ea6264 100644
--- a/wired/ethdev.c
+++ b/wired/ethdev.c
@@ -24,6 +24,7 @@
 #include <config.h>
 #endif
 
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <errno.h>
 #include <unistd.h>