diff --git a/tests/pcap_parse.c b/tests/pcap_parse.c
index 4b5a1fe5..850e1fe0 100644
--- a/tests/pcap_parse.c
+++ b/tests/pcap_parse.c
@@ -31,7 +31,8 @@
 #include "config.h"
 #endif
 
-#define _DEFAULT_SOURCE
+#define _GNU_SOURCE
+
 
 #include <inttypes.h>
 #include <stdlib.h>