/* open connection to IMAP server */
 
        if (srvc->tunnel) {
-               const char *argv[4];
+               const char *argv[] = { srvc->tunnel, NULL };
                struct child_process tunnel = {0};
 
                imap_info("Starting tunnel '%s'... ", srvc->tunnel);
 
-               argv[0] = "sh";
-               argv[1] = "-c";
-               argv[2] = srvc->tunnel;
-               argv[3] = NULL;
-
                tunnel.argv = argv;
+               tunnel.use_shell = 1;
                tunnel.in = -1;
                tunnel.out = -1;
                if (start_command(&tunnel))