diff --git a/td/mtproto/PingConnection.cpp b/td/mtproto/PingConnection.cpp
index 0ca9b1c20..f9face7e0 100644
--- a/td/mtproto/PingConnection.cpp
+++ b/td/mtproto/PingConnection.cpp
@@ -75,7 +75,6 @@ class PingConnectionPingPong
   PingConnectionPingPong(unique_ptr<mtproto::RawConnection> raw_connection, unique_ptr<mtproto::AuthData> auth_data)
       : auth_data_(std::move(auth_data)) {
     auth_data_->set_header("");
-    auth_data_->set_session_id(static_cast<uint64>(Random::secure_int64()));
     connection_ =
         make_unique<SessionConnection>(SessionConnection::Mode::Tcp, std::move(raw_connection), auth_data_.get());
   }
diff --git a/td/telegram/net/ConnectionCreator.cpp b/td/telegram/net/ConnectionCreator.cpp
index 8fa9fc174..d0c303d18 100644
--- a/td/telegram/net/ConnectionCreator.cpp
+++ b/td/telegram/net/ConnectionCreator.cpp
@@ -32,6 +32,7 @@
 #include "td/utils/logging.h"
 #include "td/utils/misc.h"
 #include "td/utils/port/IPAddress.h"
+#include "td/utils/Random.h"
 #include "td/utils/ScopeGuard.h"
 #include "td/utils/Time.h"
 #include "td/utils/tl_helpers.h"
@@ -190,6 +191,25 @@ ConnectionCreator::ClientInfo::ClientInfo() {
   mtproto_error_flood_control.add_limit(8, 3);
 }
 
+int64 ConnectionCreator::ClientInfo::extract_session_id() {
+  if (!session_ids_.empty()) {
+    auto res = *session_ids_.begin();
+    session_ids_.erase(session_ids_.begin());
+    return res;
+  }
+  int64 res = 0;
+  while (res == 0) {
+    res = Random::secure_int64();
+  }
+  return res;
+}
+
+void ConnectionCreator::ClientInfo::add_session_id(int64 session_id) {
+  if (session_id != 0) {
+    session_ids_.insert(session_id);
+  }
+}
+
 ConnectionCreator::ConnectionCreator(ActorShared<> parent) : parent_(std::move(parent)) {
 }
 
@@ -1014,6 +1034,7 @@ void ConnectionCreator::client_create_raw_connection(Result<ConnectionData> r_co
                                                      string debug_str, uint32 network_generation) {
   unique_ptr<mtproto::AuthData> auth_data;
   uint64 auth_data_generation{0};
+  int64 session_id{0};
   if (check_mode) {
     auto it = clients_.find(hash);
     CHECK(it != clients_.end());
@@ -1021,9 +1042,11 @@ void ConnectionCreator::client_create_raw_connection(Result<ConnectionData> r_co
     if (auth_data_ptr && auth_data_ptr->use_pfs() && auth_data_ptr->has_auth_key(Time::now_cached())) {
       auth_data = make_unique<mtproto::AuthData>(*auth_data_ptr);
       auth_data_generation = it->second.auth_data_generation;
+      session_id = it->second.extract_session_id();
+      auth_data->set_session_id(session_id);
     }
   }
-  auto promise = PromiseCreator::lambda([actor_id = actor_id(this), hash, check_mode, auth_data_generation,
+  auto promise = PromiseCreator::lambda([actor_id = actor_id(this), hash, check_mode, auth_data_generation, session_id,
                                          debug_str](Result<unique_ptr<mtproto::RawConnection>> result) mutable {
     if (result.is_ok()) {
       VLOG(connections) << "Ready connection (" << (check_mode ? "" : "un") << "checked) " << result.ok().get() << ' '
@@ -1033,7 +1056,7 @@ void ConnectionCreator::client_create_raw_connection(Result<ConnectionData> r_co
                         << debug_str;
     }
     send_closure(std::move(actor_id), &ConnectionCreator::client_add_connection, hash, std::move(result), check_mode,
-                 auth_data_generation);
+                 auth_data_generation, session_id);
   });
 
   if (r_connection_data.is_error()) {
@@ -1068,8 +1091,9 @@ void ConnectionCreator::client_set_timeout_at(ClientInfo &client, double wakeup_
 }
 
 void ConnectionCreator::client_add_connection(size_t hash, Result<unique_ptr<mtproto::RawConnection>> r_raw_connection,
-                                              bool check_flag, uint64 auth_data_generation) {
+                                              bool check_flag, uint64 auth_data_generation, int64 session_id) {
   auto &client = clients_[hash];
+  client.add_session_id(session_id);
   CHECK(client.pending_connections > 0);
   client.pending_connections--;
   if (check_flag) {
diff --git a/td/telegram/net/ConnectionCreator.h b/td/telegram/net/ConnectionCreator.h
index 5b13e3cf7..5b807d03f 100644
--- a/td/telegram/net/ConnectionCreator.h
+++ b/td/telegram/net/ConnectionCreator.h
@@ -221,6 +221,8 @@ class ConnectionCreator : public NetQueryCallback {
       int32 next_delay_ = 1;
     };
     ClientInfo();
+    int64 extract_session_id();
+    void add_session_id(int64 session_id);
 
     Backoff backoff;
     FloodControlStrict flood_control;
@@ -239,6 +241,7 @@ class ConnectionCreator : public NetQueryCallback {
     DcId dc_id;
     bool allow_media_only;
     bool is_media;
+    std::set<int64> session_ids_;
     unique_ptr<mtproto::AuthData> auth_data;
     uint64 auth_data_generation{0};
   };
@@ -303,7 +306,7 @@ class ConnectionCreator : public NetQueryCallback {
                                     mtproto::TransportType transport_type, size_t hash, string debug_str,
                                     uint32 network_generation);
   void client_add_connection(size_t hash, Result<unique_ptr<mtproto::RawConnection>> r_raw_connection, bool check_flag,
-                             uint64 auth_data_generation);
+                             uint64 auth_data_generation, int64 session_id);
   void client_set_timeout_at(ClientInfo &client, double wakeup_at);
 
   void on_get_proxy_info(telegram_api::object_ptr<telegram_api::help_ProxyData> proxy_data_ptr);