diff --git a/chmod_chown_chgrp.c b/chmod_chown_chgrp.c
index f6ecfd6..08ea6ee 100644
--- a/chmod_chown_chgrp.c
+++ b/chmod_chown_chgrp.c
@@ -29,6 +29,9 @@
 #include "messages.c"
 
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
 
 static long uid = -1;