diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 9e578fd738be8ff5d21a026fb44de3a93cf12d09..2bc0e3f2b2498de8c069c122a55566f2fac33573 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -589,7 +589,7 @@ int num;
 
 int SSL_write(s,buf,num)
 SSL *s;
-char *buf;
+const char *buf;
 int num;
 	{
 	if (s->shutdown & SSL_SENT_SHUTDOWN)