--- src/dtmf.cpp.orig	Fri Feb 20 17:23:13 2004
+++ src/dtmf.cpp	Fri Feb 20 17:23:19 2004
@@ -30,6 +30,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <time.h>
 #include <fcntl.h>
 #include "audio.h"