diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b810f650..14139ea7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -157,7 +157,7 @@ jobs:
     - name: Build ngtcp2
       if: matrix.http3 == 'http3'
       run: |
-        git clone --depth 1 -b v0.9.0 https://github.com/ngtcp2/ngtcp2
+        git clone --depth 1 -b v0.10.0 https://github.com/ngtcp2/ngtcp2
         cd ngtcp2
         autoreconf -i
         ./configure --prefix=$PWD/build --enable-lib-only PKG_CONFIG_PATH="../openssl/build/lib/pkgconfig" $EXTRA_NGTCP2_OPTS
diff --git a/README.rst b/README.rst
index 5cc6fbd6..28984dc3 100644
--- a/README.rst
+++ b/README.rst
@@ -143,7 +143,7 @@ following libraries are required:
   <https://github.com/quictls/openssl/tree/OpenSSL_1_1_1q+quic>`_; or
   `BoringSSL <https://boringssl.googlesource.com/boringssl/>`_ (commit
   04989786e9ab16cef5261bbd05a2b1a8cb312dbf)
-* `ngtcp2 <https://github.com/ngtcp2/ngtcp2>`_ >= 0.9.0
+* `ngtcp2 <https://github.com/ngtcp2/ngtcp2>`_ >= 0.10.0
 * `nghttp3 <https://github.com/ngtcp2/nghttp3>`_ >= 0.7.0
 
 Use ``--enable-http3`` configure option to enable HTTP/3 feature for
@@ -379,7 +379,7 @@ Build ngtcp2:
 
 .. code-block:: text
 
-   $ git clone --depth 1 -b v0.9.0 https://github.com/ngtcp2/ngtcp2
+   $ git clone --depth 1 -b v0.10.0 https://github.com/ngtcp2/ngtcp2
    $ cd ngtcp2
    $ autoreconf -i
    $ ./configure --prefix=$PWD/build --enable-lib-only \
diff --git a/configure.ac b/configure.ac
index 6f8f08fe..eb3b3365 100644
--- a/configure.ac
+++ b/configure.ac
@@ -540,7 +540,7 @@ fi
 # ngtcp2 (for src)
 have_libngtcp2=no
 if test "x${request_libngtcp2}" != "xno"; then
-  PKG_CHECK_MODULES([LIBNGTCP2], [libngtcp2 >= 0.9.0], [have_libngtcp2=yes],
+  PKG_CHECK_MODULES([LIBNGTCP2], [libngtcp2 >= 0.10.0], [have_libngtcp2=yes],
                     [have_libngtcp2=no])
   if test "x${have_libngtcp2}" = "xno"; then
     AC_MSG_NOTICE($LIBNGTCP2_PKG_ERRORS)
@@ -557,7 +557,7 @@ have_libngtcp2_crypto_openssl=no
 if test "x${have_ssl_is_quic}" = "xyes" &&
    test "x${request_libngtcp2}" != "xno"; then
   PKG_CHECK_MODULES([LIBNGTCP2_CRYPTO_OPENSSL],
-                    [libngtcp2_crypto_openssl >= 0.9.0],
+                    [libngtcp2_crypto_openssl >= 0.10.0],
                     [have_libngtcp2_crypto_openssl=yes],
                     [have_libngtcp2_crypto_openssl=no])
   if test "x${have_libngtcp2_crypto_openssl}" = "xno"; then
diff --git a/docker/Dockerfile b/docker/Dockerfile
index 16cef814..e96e3605 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -24,7 +24,7 @@ RUN git clone --depth 1 -b v0.7.1 https://github.com/ngtcp2/nghttp3 && \
     cd .. && \
     rm -rf nghttp3
 
-RUN git clone --depth 1 -b v0.9.0 https://github.com/ngtcp2/ngtcp2 && \
+RUN git clone --depth 1 -b v0.10.0 https://github.com/ngtcp2/ngtcp2 && \
     cd ngtcp2 && \
     autoreconf -i && \
     ./configure --enable-lib-only \
diff --git a/src/h2load_quic.cc b/src/h2load_quic.cc
index e9b98e4e..d165cdb3 100644
--- a/src/h2load_quic.cc
+++ b/src/h2load_quic.cc
@@ -387,8 +387,8 @@ int Client::quic_init(const sockaddr *local_addr, socklen_t local_addrlen,
     settings.qlog.write = qlog_write_cb;
   }
   if (config->max_udp_payload_size) {
-    settings.max_udp_payload_size = config->max_udp_payload_size;
-    settings.no_udp_payload_size_shaping = 1;
+    settings.max_tx_udp_payload_size = config->max_udp_payload_size;
+    settings.no_tx_udp_payload_size_shaping = 1;
   }
 
   ngtcp2_transport_params params;
@@ -592,14 +592,14 @@ int Client::write_quic() {
 
   std::array<nghttp3_vec, 16> vec;
   size_t pktcnt = 0;
-  auto max_udp_payload_size = ngtcp2_conn_get_max_udp_payload_size(quic.conn);
+  auto max_udp_payload_size =
+      ngtcp2_conn_get_max_tx_udp_payload_size(quic.conn);
 #ifdef UDP_SEGMENT
   auto path_max_udp_payload_size =
-      ngtcp2_conn_get_path_max_udp_payload_size(quic.conn);
+      ngtcp2_conn_get_path_max_tx_udp_payload_size(quic.conn);
 #endif // UDP_SEGMENT
-  size_t max_pktcnt =
-      std::min(static_cast<size_t>(10),
-               static_cast<size_t>(64_k / max_udp_payload_size));
+  auto max_pktcnt =
+      ngtcp2_conn_get_send_quantum(quic.conn) / max_udp_payload_size;
   uint8_t *bufpos = quic.tx.data.get();
   ngtcp2_path_storage ps;
   size_t gso_size = 0;
diff --git a/src/shrpx_http3_upstream.cc b/src/shrpx_http3_upstream.cc
index 1d530621..ac3399d7 100644
--- a/src/shrpx_http3_upstream.cc
+++ b/src/shrpx_http3_upstream.cc
@@ -611,7 +611,7 @@ int Http3Upstream::init(const UpstreamAddr *faddr, const Address &remote_addr,
   settings.cc_algo = quicconf.upstream.congestion_controller;
   settings.max_window = http3conf.upstream.max_connection_window_size;
   settings.max_stream_window = http3conf.upstream.max_window_size;
-  settings.max_udp_payload_size = SHRPX_QUIC_MAX_UDP_PAYLOAD_SIZE;
+  settings.max_tx_udp_payload_size = SHRPX_QUIC_MAX_UDP_PAYLOAD_SIZE;
   settings.rand_ctx.native_handle = &worker->get_randgen();
   settings.token = ngtcp2_vec{const_cast<uint8_t *>(token), tokenlen};
 
@@ -738,14 +738,12 @@ int Http3Upstream::on_write() {
 
 int Http3Upstream::write_streams() {
   std::array<nghttp3_vec, 16> vec;
-  auto max_udp_payload_size = ngtcp2_conn_get_max_udp_payload_size(conn_);
+  auto max_udp_payload_size = ngtcp2_conn_get_max_tx_udp_payload_size(conn_);
 #ifdef UDP_SEGMENT
   auto path_max_udp_payload_size =
-      ngtcp2_conn_get_path_max_udp_payload_size(conn_);
+      ngtcp2_conn_get_path_max_tx_udp_payload_size(conn_);
 #endif // UDP_SEGMENT
-  size_t max_pktcnt =
-      std::min(static_cast<size_t>(64_k), ngtcp2_conn_get_send_quantum(conn_)) /
-      max_udp_payload_size;
+  auto max_pktcnt = ngtcp2_conn_get_send_quantum(conn_) / max_udp_payload_size;
   ngtcp2_pkt_info pi, prev_pi;
   uint8_t *bufpos = tx_.data.get();
   ngtcp2_path_storage ps, prev_ps;