diff --git a/net.c b/net.c
index db2f8d345e..7ae1e6d60c 100644
--- a/net.c
+++ b/net.c
@@ -620,7 +620,7 @@ void net_slirp_redir(Monitor *mon, const char *redir_str)
     errmsg = "invalid redirection format\n";
  fail:
     if (mon) {
-        monitor_printf(mon, errmsg);
+        monitor_printf(mon, "%s", errmsg);
     } else {
         fprintf(stderr, "qemu: %s", errmsg);
         exit(1);