diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 60ed9aa9e..aecd94228 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -1,8 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1+ */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE 1
-#endif
+#include "config.h"
+
 #include <arpa/inet.h>
 #include <dirent.h>
 #include <errno.h>
@@ -39,7 +38,6 @@
 #include "caps.h"
 #include "cgroups/cgroup.h"
 #include "compiler.h"
-#include "config.h"
 #include "confile.h"
 #include "confile_utils.h"
 #include "error.h"
diff --git a/src/lxc/conf.h b/src/lxc/conf.h
index 24bf1b71b..636b9017d 100644
--- a/src/lxc/conf.h
+++ b/src/lxc/conf.h
@@ -3,9 +3,8 @@
 #ifndef __LXC_CONF_H
 #define __LXC_CONF_H
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE 1
-#endif
+#include "config.h"
+
 #include <linux/magic.h>
 #include <net/if.h>
 #include <netinet/in.h>
@@ -18,7 +17,6 @@
 #include "attach_options.h"
 #include "caps.h"
 #include "compiler.h"
-#include "config.h"
 #include "hlist.h"
 #include "list.h"
 #include "lxcseccomp.h"