diff --git a/lib/vquic/curl_ngtcp2.c b/lib/vquic/curl_ngtcp2.c
index 04c6ed1fee..b5be05afc7 100644
--- a/lib/vquic/curl_ngtcp2.c
+++ b/lib/vquic/curl_ngtcp2.c
@@ -2244,8 +2244,8 @@ static CURLcode cf_ngtcp2_shutdown(struct Curl_cfilter *cf,
       (uint8_t *)buffer, sizeof(buffer),
       &ctx->last_error, pktx.ts);
     CURL_TRC_CF(data, cf, "start shutdown(err_type=%d, err_code=%"
-                PRIu64 ") -> %d", ctx->last_error.type,
-                ctx->last_error.error_code, (int)nwritten);
+                PRIu64 ") -> %zd", ctx->last_error.type,
+                ctx->last_error.error_code, (ssize_t)nwritten);
     /* there are cases listed in ngtcp2 documentation where this call
      * may fail. Since we are doing a connection shutdown as graceful
      * as we can, such an error is ignored here. */