diff --git a/testsuite/ltrace.minor/trace-clone.c b/testsuite/ltrace.minor/trace-clone.c
index a1ccb22..6e1c809 100644
--- a/testsuite/ltrace.minor/trace-clone.c
+++ b/testsuite/ltrace.minor/trace-clone.c
@@ -4,6 +4,7 @@
This file was written by Yao Qi <qiyao@cn.ibm.com>. */
+#define _GNU_SOURCE
#include <stdio.h>
#include <sys/types.h>
#include <stdlib.h>