diff --git a/posixtz.c b/posixtz.c
index cddcb3e..ec32239 100644
--- a/posixtz.c
+++ b/posixtz.c
@@ -14,6 +14,8 @@
 #include <fcntl.h>
 #include <limits.h>
 #include <stdio.h>
+#include <string.h>
+#include <unistd.h>
 
 #include "posixtz.h"