diff --git a/lib/vquic/ngtcp2.c b/lib/vquic/ngtcp2.c
index 9dd4fa2147..a58cf7f079 100644
--- a/lib/vquic/ngtcp2.c
+++ b/lib/vquic/ngtcp2.c
@@ -73,7 +73,7 @@
  * the far end, then start over at index 0 again.
  */
 
-#define H3_SEND_SIZE (20*1024)
+#define H3_SEND_SIZE (256*1024)
 struct h3out {
   uint8_t buf[H3_SEND_SIZE];
   size_t used;   /* number of bytes used in the buffer */