diff --git a/external/ngtcp2 b/external/ngtcp2
index 51e95c8d8..15ba6021c 160000
--- a/external/ngtcp2
+++ b/external/ngtcp2
@@ -1 +1 @@
-Subproject commit 51e95c8d8972abd69515d9790e8fbb774262d9ea
+Subproject commit 15ba6021ca352e2e60f9b43f4b96d2e97a42f60b
diff --git a/llarp/quic/address.hpp b/llarp/quic/address.hpp
index 42150ed3e..5f7bc3522 100644
--- a/llarp/quic/address.hpp
+++ b/llarp/quic/address.hpp
@@ -21,7 +21,7 @@ namespace llarp::quic
   class Address
   {
     sockaddr_in6 saddr{};
-    ngtcp2_addr a{sizeof(saddr), reinterpret_cast<sockaddr*>(&saddr), nullptr};
+    ngtcp2_addr a{sizeof(saddr), reinterpret_cast<sockaddr*>(&saddr)};
 
    public:
     Address() = default;
@@ -102,8 +102,7 @@ namespace llarp::quic
     Address local_, remote_;
 
    public:
-    ngtcp2_path path{
-        {local_.sockaddr_size(), local_, nullptr}, {remote_.sockaddr_size(), remote_, nullptr}};
+    ngtcp2_path path{{local_.sockaddr_size(), local_}, {remote_.sockaddr_size(), remote_}, nullptr};
 
     // Public accessors are const:
     const Address& local = local_;
diff --git a/llarp/quic/connection.cpp b/llarp/quic/connection.cpp
index c3b21d597..8d7cc8728 100644
--- a/llarp/quic/connection.cpp
+++ b/llarp/quic/connection.cpp
@@ -244,6 +244,7 @@ namespace llarp::quic
     int
     stream_close_cb(
         ngtcp2_conn* conn,
+        uint32_t flags,
         int64_t stream_id,
         uint64_t app_error_code,
         void* user_data,
@@ -275,17 +276,13 @@ namespace llarp::quic
       return 0;
     }
 
-    int
-    rand(
-        uint8_t* dest,
-        size_t destlen,
-        const ngtcp2_rand_ctx* rand_ctx,
-        [[maybe_unused]] ngtcp2_rand_usage usage)
+    void
+    rand(uint8_t* dest, size_t destlen, const ngtcp2_rand_ctx* rand_ctx)
     {
       LogTrace("######################", __func__);
       randombytes_buf(dest, destlen);
-      return 0;
     }
+
     int
     get_new_connection_id(
         ngtcp2_conn* conn_, ngtcp2_cid* cid_, uint8_t* token, size_t cidlen, void* user_data)
@@ -406,7 +403,7 @@ namespace llarp::quic
 
     settings.initial_ts = get_timestamp();
     // FIXME: IPv6
-    settings.max_udp_payload_size = NGTCP2_MAX_PKTLEN_IPV4;
+    settings.max_udp_payload_size = Endpoint::max_pkt_size_v4;
     settings.cc_algo = NGTCP2_CC_ALGO_CUBIC;
     // settings.initial_rtt = ???; # NGTCP2's default is 333ms
 
@@ -1185,8 +1182,7 @@ namespace llarp::quic
     ngtcp2_conn_get_local_transport_params(*this, &tparams);
 
     assert(conn_buffer.empty());
-    static_assert(NGTCP2_MAX_PKTLEN_IPV4 > NGTCP2_MAX_PKTLEN_IPV6);
-    conn_buffer.resize(NGTCP2_MAX_PKTLEN_IPV4);
+    conn_buffer.resize(Endpoint::max_pkt_size_v4);
 
     auto* buf = u8data(conn_buffer);
     auto* bufend = buf + conn_buffer.size();
diff --git a/llarp/quic/connection.hpp b/llarp/quic/connection.hpp
index 828e99d23..be8eb715c 100644
--- a/llarp/quic/connection.hpp
+++ b/llarp/quic/connection.hpp
@@ -123,7 +123,7 @@ namespace llarp::quic
     };
 
     // Packet data storage for a packet we are currently sending
-    std::array<std::byte, NGTCP2_MAX_PKTLEN_IPV4> send_buffer{};
+    std::array<std::byte, NGTCP2_MAX_UDP_PAYLOAD_SIZE> send_buffer{};
     size_t send_buffer_size = 0;
     ngtcp2_pkt_info send_pkt_info{};
 
diff --git a/llarp/quic/endpoint.cpp b/llarp/quic/endpoint.cpp
index 16444c1a4..5d57e9010 100644
--- a/llarp/quic/endpoint.cpp
+++ b/llarp/quic/endpoint.cpp
@@ -199,7 +199,7 @@ namespace llarp::quic
   void
   Endpoint::send_version_negotiation(const version_info& vi, const Address& source)
   {
-    std::array<std::byte, NGTCP2_MAX_PKTLEN_IPV4> buf;
+    std::array<std::byte, Endpoint::max_pkt_size_v4> buf;
     std::array<uint32_t, NGTCP2_PROTO_VER_MAX - NGTCP2_PROTO_VER_MIN + 2> versions;
     std::iota(versions.begin() + 1, versions.end(), NGTCP2_PROTO_VER_MIN);
     // we're supposed to send some 0x?a?a?a?a version to trigger version negotiation
@@ -234,11 +234,13 @@ namespace llarp::quic
       Path path;
       ngtcp2_pkt_info pi;
 
-      auto write_close_func =
-          application ? ngtcp2_conn_write_application_close : ngtcp2_conn_write_connection_close;
+      auto write_close_func = application ? ngtcp2_conn_write_application_close_versioned
+                                          : ngtcp2_conn_write_connection_close_versioned;
+
       auto written = write_close_func(
           conn,
           path,
+          NGTCP2_PKT_INFO_VERSION,
           &pi,
           u8data(conn.conn_buffer),
           conn.conn_buffer.size(),
diff --git a/llarp/quic/endpoint.hpp b/llarp/quic/endpoint.hpp
index 53a850ea4..cfbf92c54 100644
--- a/llarp/quic/endpoint.hpp
+++ b/llarp/quic/endpoint.hpp
@@ -64,8 +64,8 @@ namespace llarp::quic
     // Max theoretical size of a UDP packet is 2^16-1 minus IP/UDP header overhead
     static constexpr size_t max_buf_size = 64 * 1024;
     // Max size of a UDP packet that we'll send
-    static constexpr size_t max_pkt_size_v4 = NGTCP2_MAX_PKTLEN_IPV4;
-    static constexpr size_t max_pkt_size_v6 = NGTCP2_MAX_PKTLEN_IPV6;
+    static constexpr size_t max_pkt_size_v4 = NGTCP2_MAX_UDP_PAYLOAD_SIZE;
+    static constexpr size_t max_pkt_size_v6 = NGTCP2_MAX_UDP_PAYLOAD_SIZE;
 
     using primary_conn_ptr = std::shared_ptr<Connection>;
     using alias_conn_ptr = std::weak_ptr<Connection>;