diff --git a/btrfs-list.c b/btrfs-list.c
index 77417059..9dedb5d2 100644
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -16,6 +16,7 @@
  * Boston, MA 021110-1307, USA.
  */
 
+#define _GNU_SOURCE
 #ifndef __CHECKER__
 #include <sys/ioctl.h>
 #include <sys/mount.h>
diff --git a/btrfs.c b/btrfs.c
index ab5e57fe..46314cfe 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -14,7 +14,7 @@
  * Boston, MA 021110-1307, USA.
  */
 
-
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>