1 files changed, 2 insertions, 0 deletions

diff --git a/testing/tox_shell.c b/testing/tox_shell.c
index 18aad9c7..d5de3e67 100644
--- a/testing/tox_shell.c
+++ b/testing/tox_shell.c
@@ -26,6 +26,8 @@
  *
  */
 
+#define _XOPEN_SOURCE 600
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif