diff --git a/socket.c b/socket.c
index fc01edf9..5843325a 100644
--- a/socket.c
+++ b/socket.c
@@ -52,7 +52,7 @@ static int establish_proxy_connection(int fd, char *host, int port,
 			 proxy_user, proxy_pass);
 		len = strlen(buffer);
 
-		if ((len*8 + 5) / 6 - 2 >= (int)sizeof authbuf) {
+		if ((len*8 + 5) / 6 >= (int)sizeof authbuf) {
 			rprintf(FERROR,
 				"authentication information is too long\n");
 			return -1;