diff --git a/td/telegram/FileReferenceManager.cpp b/td/telegram/FileReferenceManager.cpp
index cb3be3837..441c4eb45 100644
--- a/td/telegram/FileReferenceManager.cpp
+++ b/td/telegram/FileReferenceManager.cpp
@@ -37,7 +37,7 @@ FileReferenceManager::FileReferenceManager(ActorShared<> parent) : parent_(std::
 }
 
 FileReferenceManager::~FileReferenceManager() {
-  Scheduler::instance()->destroy_on_scheduler(G()->get_gc_scheduler_id(), file_sources_);
+  Scheduler::instance()->destroy_on_scheduler(G()->get_gc_scheduler_id(), file_sources_, nodes_);
 }
 
 void FileReferenceManager::tear_down() {
@@ -155,16 +155,26 @@ FileSourceId FileReferenceManager::create_attach_menu_bot_file_source(UserId use
   return add_file_source_id(source, PSLICE() << "attachment menu bot " << user_id);
 }
 
-bool FileReferenceManager::add_file_source(NodeId node_id, FileSourceId file_source_id) {
+FileReferenceManager::Node &FileReferenceManager::add_node(NodeId node_id) {
   CHECK(node_id.is_valid());
-  bool is_added = nodes_[node_id].file_source_ids.add(file_source_id);
+  auto &node = nodes_[node_id];
+  if (node == nullptr) {
+    node = make_unique<Node>();
+  }
+  return *node;
+}
+
+bool FileReferenceManager::add_file_source(NodeId node_id, FileSourceId file_source_id) {
+  auto &node = add_node(node_id);
+  bool is_added = node.file_source_ids.add(file_source_id);
   VLOG(file_references) << "Add " << (is_added ? "new" : "old") << ' ' << file_source_id << " for file " << node_id;
   return is_added;
 }
 
 bool FileReferenceManager::remove_file_source(NodeId node_id, FileSourceId file_source_id) {
   CHECK(node_id.is_valid());
-  bool is_removed = nodes_[node_id].file_source_ids.remove(file_source_id);
+  auto *node = nodes_.get_pointer(node_id);
+  bool is_removed = node != nullptr && node->file_source_ids.remove(file_source_id);
   if (is_removed) {
     VLOG(file_references) << "Remove " << file_source_id << " from file " << node_id;
   } else {
@@ -174,11 +184,11 @@ bool FileReferenceManager::remove_file_source(NodeId node_id, FileSourceId file_
 }
 
 vector<FileSourceId> FileReferenceManager::get_some_file_sources(NodeId node_id) {
-  auto it = nodes_.find(node_id);
-  if (it == nodes_.end()) {
+  auto *node = nodes_.get_pointer(node_id);
+  if (node == nullptr) {
     return {};
   }
-  return it->second.file_source_ids.get_some_elements();
+  return node->file_source_ids.get_some_elements();
 }
 
 vector<FullMessageId> FileReferenceManager::get_some_message_file_sources(NodeId node_id) {
@@ -197,14 +207,13 @@ vector<FullMessageId> FileReferenceManager::get_some_message_file_sources(NodeId
 }
 
 void FileReferenceManager::merge(NodeId to_node_id, NodeId from_node_id) {
-  auto from_it = nodes_.find(from_node_id);
-  if (from_it == nodes_.end()) {
+  auto *from_node_ptr = nodes_.get_pointer(from_node_id);
+  if (from_node_ptr == nullptr) {
     return;
   }
+  auto &from = *from_node_ptr;
 
-  CHECK(to_node_id.is_valid());
-  auto &to = nodes_[to_node_id];
-  auto &from = from_it->second;
+  auto &to = add_node(to_node_id);
   VLOG(file_references) << "Merge " << to.file_source_ids.size() << " and " << from.file_source_ids.size()
                         << " sources of files " << to_node_id << " and " << from_node_id;
   CHECK(!to.query || to.query->proxy.is_empty());
@@ -227,7 +236,11 @@ void FileReferenceManager::merge(NodeId to_node_id, NodeId from_node_id) {
 
 void FileReferenceManager::run_node(NodeId node_id) {
   CHECK(node_id.is_valid());
-  Node &node = nodes_[node_id];
+  auto *node_ptr = nodes_.get_pointer(node_id);
+  if (node_ptr == nullptr) {
+    return;
+  }
+  Node &node = *node_ptr;
   if (!node.query) {
     return;
   }
@@ -266,8 +279,7 @@ void FileReferenceManager::run_node(NodeId node_id) {
 void FileReferenceManager::send_query(Destination dest, FileSourceId file_source_id) {
   VLOG(file_references) << "Send file reference repair query for file " << dest.node_id << " with generation "
                         << dest.generation << " from " << file_source_id;
-  CHECK(dest.node_id.is_valid());
-  auto &node = nodes_[dest.node_id];
+  auto &node = add_node(dest.node_id);
   node.query->active_queries++;
 
   auto promise = PromiseCreator::lambda([dest, file_source_id, actor_id = actor_id(this),
@@ -361,8 +373,7 @@ FileReferenceManager::Destination FileReferenceManager::on_query_result(Destinat
   VLOG(file_references) << "Receive result of file reference repair query for file " << dest.node_id
                         << " with generation " << dest.generation << " from " << file_source_id << ": " << status << " "
                         << sub;
-  CHECK(dest.node_id.is_valid());
-  auto &node = nodes_[dest.node_id];
+  auto &node = add_node(dest.node_id);
 
   auto query = node.query.get();
   if (!query) {
@@ -399,8 +410,7 @@ void FileReferenceManager::repair_file_reference(NodeId node_id, Promise<> promi
   auto main_file_id = G()->td().get_actor_unsafe()->file_manager_->get_file_view(node_id).get_main_file_id();
   VLOG(file_references) << "Repair file reference for file " << node_id << "/" << main_file_id;
   node_id = main_file_id;
-  CHECK(node_id.is_valid());
-  auto &node = nodes_[node_id];
+  auto &node = add_node(node_id);
   if (!node.query) {
     node.query = make_unique<Query>();
     node.query->generation = ++query_generation_;
diff --git a/td/telegram/FileReferenceManager.h b/td/telegram/FileReferenceManager.h
index c16976624..2f96ff2e4 100644
--- a/td/telegram/FileReferenceManager.h
+++ b/td/telegram/FileReferenceManager.h
@@ -20,12 +20,12 @@
 #include "td/actor/actor.h"
 
 #include "td/utils/common.h"
-#include "td/utils/FlatHashMap.h"
 #include "td/utils/logging.h"
 #include "td/utils/Promise.h"
 #include "td/utils/Slice.h"
 #include "td/utils/Status.h"
 #include "td/utils/Variant.h"
+#include "td/utils/WaitFreeHashMap.h"
 #include "td/utils/WaitFreeVector.h"
 
 namespace td {
@@ -175,10 +175,12 @@ class FileReferenceManager final : public Actor {
 
   int64 query_generation_{0};
 
-  FlatHashMap<NodeId, Node, FileIdHash> nodes_;
+  WaitFreeHashMap<NodeId, unique_ptr<Node>, FileIdHash> nodes_;
 
   ActorShared<> parent_;
 
+  Node &add_node(NodeId node_id);
+
   void run_node(NodeId node);
   void send_query(Destination dest, FileSourceId file_source_id);
   Destination on_query_result(Destination dest, FileSourceId file_source_id, Status status, int32 sub = 0);