diff --git a/lib/vquic/ngtcp2.c b/lib/vquic/ngtcp2.c
index d5204ab6af..e8c013e5d8 100644
--- a/lib/vquic/ngtcp2.c
+++ b/lib/vquic/ngtcp2.c
@@ -1918,8 +1918,9 @@ static CURLcode do_sendmsg(size_t *psent, struct Curl_easy *data, int sockfd,
       return CURLE_SEND_ERROR;
     }
   }
-
-  assert(pktlen == (size_t)sent);
+  else {
+    assert(pktlen == (size_t)sent);
+  }
 
   *psent = pktlen;