diff --git a/tonlib/tonlib/LastConfig.cpp b/tonlib/tonlib/LastConfig.cpp
index 5ee73212..0111095b 100644
--- a/tonlib/tonlib/LastConfig.cpp
+++ b/tonlib/tonlib/LastConfig.cpp
@@ -39,7 +39,7 @@ td::StringBuilder& operator<<(td::StringBuilder& sb, const LastConfigState& stat
   return sb;
 }
 
-LastConfig::LastConfig(ExtClientRef client) {
+LastConfig::LastConfig(ExtClientRef client, td::unique_ptr<Callback> callback) : callback_(std::move(callback)) {
   client_.set_client(client);
   VLOG(last_block) << "State: " << state_;
 }
diff --git a/tonlib/tonlib/LastConfig.h b/tonlib/tonlib/LastConfig.h
index d610165d..514b4a59 100644
--- a/tonlib/tonlib/LastConfig.h
+++ b/tonlib/tonlib/LastConfig.h
@@ -36,10 +36,17 @@ td::StringBuilder& operator<<(td::StringBuilder& sb, const LastConfigState& stat
 
 class LastConfig : public td::actor::Actor {
  public:
-  explicit LastConfig(ExtClientRef client);
+  class Callback {
+   public:
+    virtual ~Callback() {
+    }
+  };
+
+  explicit LastConfig(ExtClientRef client, td::unique_ptr<Callback> callback);
   void get_last_config(td::Promise<LastConfigState> promise);
 
  private:
+  td::unique_ptr<Callback> callback_;
   ExtClient client_;
   LastConfigState state_;
 
diff --git a/tonlib/tonlib/TonlibClient.cpp b/tonlib/tonlib/TonlibClient.cpp
index 8bcf53c9..2696bb1a 100644
--- a/tonlib/tonlib/TonlibClient.cpp
+++ b/tonlib/tonlib/TonlibClient.cpp
@@ -1439,9 +1439,17 @@ void TonlibClient::init_last_block(LastBlockState state) {
 }
 void TonlibClient::init_last_config() {
   ref_cnt_++;
+  class Callback : public LastConfig::Callback {
+   public:
+    Callback(td::actor::ActorShared<TonlibClient> client) : client_(std::move(client)) {
+    }
+
+   private:
+    td::actor::ActorShared<TonlibClient> client_;
+  };
   raw_last_config_ =
       td::actor::create_actor<LastConfig>(td::actor::ActorOptions().with_name("LastConfig").with_poll(false),
-                                          get_client_ref());
+                                          get_client_ref(), td::make_unique<Callback>(td::actor::actor_shared(this)));
 }
 
 void TonlibClient::on_result(td::uint64 id, tonlib_api::object_ptr<tonlib_api::Object> response) {