diff --git a/tiny.c b/tiny.c
index d001426..186ee1f 100644
--- a/tiny.c
+++ b/tiny.c
@@ -1,3 +1,4 @@
+#define _POSIX_C_SOURCE 200809L
 #include <arpa/inet.h>          /* inet_ntoa */
 #include <signal.h>
 #include <dirent.h>