diff --git a/lib/vquic/ngtcp2.c b/lib/vquic/ngtcp2.c
index f1a64eea85..7bb76e3c3d 100644
--- a/lib/vquic/ngtcp2.c
+++ b/lib/vquic/ngtcp2.c
@@ -423,7 +423,7 @@ static int alert_read_func(gnutls_session_t ssl,
   (void)alert_level;
 
   qs->tls_alert = alert_desc;
-  return 1;
+  return 0;
 }
 
 static int tp_recv_func(gnutls_session_t ssl, const uint8_t *data,