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>