include stdio.h for sprintf prototype.
diff --git a/Mac/Compat/getwd.c b/Mac/Compat/getwd.c
index 1487fb0..3f702c9 100644
--- a/Mac/Compat/getwd.c
+++ b/Mac/Compat/getwd.c
@@ -28,6 +28,7 @@
 */
 
 #include "macdefs.h"
+#include <stdio.h>
 
 #define ROOTID 2 /* Root directory ID */