diff --git a/bus/dir-watch-inotify.c b/bus/dir-watch-inotify.c
index 44ec9cf0..12fdbb07 100644
--- a/bus/dir-watch-inotify.c
+++ b/bus/dir-watch-inotify.c
@@ -24,7 +24,6 @@
 
 #include <config.h>
 
-#define _GNU_SOURCE
 #include <stdlib.h>
 #include <unistd.h>
 #include <fcntl.h>
diff --git a/configure.in b/configure.in
index 0732adcd..62312eb0 100644
--- a/configure.in
+++ b/configure.in
@@ -57,6 +57,7 @@ AC_SUBST(DBUS_VERSION)
 AC_PROG_CC
 AM_PROG_CC_C_O
 AC_PROG_CXX
+AC_USE_SYSTEM_EXTENSIONS
 AC_ISC_POSIX
 AC_HEADER_STDC
 AC_C_INLINE
diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c
index 8b225e7e..9631be18 100644
--- a/dbus/dbus-sysdeps-unix.c
+++ b/dbus/dbus-sysdeps-unix.c
@@ -22,7 +22,7 @@
  *
  */
 
-#define _GNU_SOURCE 
+#include <config.h>
 
 #include "dbus-internals.h"
 #include "dbus-sysdeps.h"