diff --git a/tools/event-debug.c b/tools/event-debug.c
index 51ed428a..574fa9ed 100644
--- a/tools/event-debug.c
+++ b/tools/event-debug.c
@@ -21,7 +21,8 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
-#define _GNU_SOURCE
+#include "config.h"
+
 #include <errno.h>
 #include <inttypes.h>
 #include <fcntl.h>