diff --git a/src/builtin.c b/src/builtin.c
index 3f7792d1..b49010a5 100644
--- a/src/builtin.c
+++ b/src/builtin.c
@@ -1,6 +1,7 @@
 #define _BSD_SOURCE
 #define _GNU_SOURCE
 #define _XOPEN_SOURCE
+#define _XOPEN_SOURCE_EXTENDED 1
 #include <sys/time.h>
 #include <stdlib.h>
 #include <stddef.h>