diff --git a/td/telegram/NotificationManager.cpp b/td/telegram/NotificationManager.cpp
index 0d77a3d8b..67cac861c 100644
--- a/td/telegram/NotificationManager.cpp
+++ b/td/telegram/NotificationManager.cpp
@@ -534,7 +534,7 @@ void NotificationManager::try_reuse_notification_group_id(NotificationGroupId gr
     flush_pending_notifications_timeout_.cancel_timeout(group_id.get());
     flush_pending_updates_timeout_.cancel_timeout(group_id.get());
     if (pending_updates_.erase(group_id.get()) == 1) {
-      on_pending_notification_update_count_changed(-1);
+      on_pending_notification_update_count_changed(-1, group_id.get(), "try_reuse_notification_group_id");
     }
   }
 
@@ -636,7 +636,7 @@ void NotificationManager::add_notification(NotificationGroupId group_id, Notific
     flush_pending_notifications_timeout_.set_timeout_at(group_id.get(), group.pending_notifications_flush_time);
   }
   if (group.pending_notifications.empty()) {
-    on_pending_notification_update_count_changed(1);
+    on_pending_notification_update_count_changed(1, group_id.get(), "add_notification");
   }
   group.pending_notifications.push_back(std::move(notification));
 }
@@ -686,7 +686,7 @@ void NotificationManager::add_update(int32 group_id, td_api::object_ptr<td_api::
   VLOG(notifications) << "Add " << as_notification_update(update.get());
   auto &updates = pending_updates_[group_id];
   if (updates.empty()) {
-    on_pending_notification_update_count_changed(1);
+    on_pending_notification_update_count_changed(1, group_id, "add_update");
   }
   updates.push_back(std::move(update));
   if (!running_get_difference_ && running_get_chat_difference_.count(group_id) == 0) {
@@ -1042,7 +1042,7 @@ void NotificationManager::flush_pending_updates(int32 group_id, const char *sour
     VLOG(notifications) << "Send " << as_notification_update(update.get());
     send_closure(G()->td(), &Td::send_update, std::move(update));
   }
-  on_pending_notification_update_count_changed(-1);
+  on_pending_notification_update_count_changed(-1, group_id, "flush_pending_updates");
 }
 
 void NotificationManager::flush_all_pending_updates(bool include_delayed_chats, const char *source) {
@@ -1238,7 +1238,7 @@ void NotificationManager::flush_pending_notifications(NotificationGroupId group_
 
   group.pending_notifications_flush_time = 0;
   group.pending_notifications.clear();
-  on_pending_notification_update_count_changed(-1);
+  on_pending_notification_update_count_changed(-1, group_id.get(), "flush_pending_notifications");
   // if we can delete a lot of notifications simultaneously
   if (group.notifications.size() > keep_notification_group_size_ + EXTRA_GROUP_SIZE &&
       group.type != NotificationGroupType::Calls) {
@@ -1447,7 +1447,7 @@ void NotificationManager::remove_notification(NotificationGroupId group_id, Noti
       if (group_it->second.pending_notifications.empty()) {
         group_it->second.pending_notifications_flush_time = 0;
         flush_pending_notifications_timeout_.cancel_timeout(group_id.get());
-        on_pending_notification_update_count_changed(-1);
+        on_pending_notification_update_count_changed(-1, group_id.get(), "remove_notification");
       }
       return promise.set_value(Unit());
     }
@@ -1550,7 +1550,7 @@ void NotificationManager::remove_notification_group(NotificationGroupId group_id
     if (group_it->second.pending_notifications.empty()) {
       group_it->second.pending_notifications_flush_time = 0;
       flush_pending_notifications_timeout_.cancel_timeout(group_id.get());
-      on_pending_notification_update_count_changed(-1);
+      on_pending_notification_update_count_changed(-1, group_id.get(), "remove_notification_group");
     }
   }
   if (new_total_count != -1) {
@@ -1964,7 +1964,7 @@ void NotificationManager::before_get_difference() {
   }
 
   running_get_difference_ = true;
-  on_pending_notification_update_count_changed(1);
+  on_pending_notification_update_count_changed(1, 0, "before_get_difference");
 }
 
 void NotificationManager::after_get_difference() {
@@ -1974,7 +1974,7 @@ void NotificationManager::after_get_difference() {
 
   CHECK(running_get_difference_);
   running_get_difference_ = false;
-  on_pending_notification_update_count_changed(-1);
+  on_pending_notification_update_count_changed(-1, 0, "after_get_difference");
   flush_pending_notifications_timeout_.set_timeout_in(0, MIN_NOTIFICATION_DELAY_MS * 1e-3);
 }
 
@@ -1995,7 +1995,7 @@ void NotificationManager::before_get_chat_difference(NotificationGroupId group_i
   VLOG(notifications) << "Before get chat difference in " << group_id;
   CHECK(group_id.is_valid());
   running_get_chat_difference_.insert(group_id.get());
-  on_pending_notification_update_count_changed(1);
+  on_pending_notification_update_count_changed(1, group_id.get(), "before_get_chat_difference");
 }
 
 void NotificationManager::after_get_chat_difference(NotificationGroupId group_id) {
@@ -2008,7 +2008,7 @@ void NotificationManager::after_get_chat_difference(NotificationGroupId group_id
   auto erased_count = running_get_chat_difference_.erase(group_id.get());
   if (erased_count == 1) {
     flush_pending_notifications_timeout_.set_timeout_in(-group_id.get(), MIN_NOTIFICATION_DELAY_MS * 1e-3);
-    on_pending_notification_update_count_changed(-1);
+    on_pending_notification_update_count_changed(-1, group_id.get(), "after_get_chat_difference");
   }
 }
 
@@ -2061,17 +2061,19 @@ void NotificationManager::destroy_all_notifications() {
 
   flush_all_pending_updates(true, "destroy_all_notifications");
   if (pending_notification_update_count_ != 0) {
-    on_pending_notification_update_count_changed(-pending_notification_update_count_);
+    on_pending_notification_update_count_changed(-pending_notification_update_count_, 0, "destroy_all_notifications");
   }
   is_destroyed_ = true;
 }
 
-void NotificationManager::on_pending_notification_update_count_changed(int32 diff) {
+void NotificationManager::on_pending_notification_update_count_changed(int32 diff, int32 notification_group_id,
+                                                                       const char *source) {
   bool had_pending = pending_notification_update_count_ != 0;
   pending_notification_update_count_ += diff;
   CHECK(pending_notification_update_count_ >= 0);
   VLOG(notifications) << "Update pending notification count with diff " << diff << " to "
-                      << pending_notification_update_count_;
+                      << pending_notification_update_count_ << " from group " << notification_group_id << " and "
+                      << source;
   bool have_pending = pending_notification_update_count_ != 0;
   if (had_pending != have_pending && !is_destroyed_) {
     auto update = td_api::make_object<td_api::updateHavePendingNotifications>(have_pending);
diff --git a/td/telegram/NotificationManager.h b/td/telegram/NotificationManager.h
index 848e80c99..0fd84e4f4 100644
--- a/td/telegram/NotificationManager.h
+++ b/td/telegram/NotificationManager.h
@@ -220,7 +220,7 @@ class NotificationManager : public Actor {
 
   void after_get_chat_difference_impl(NotificationGroupId group_id);
 
-  void on_pending_notification_update_count_changed(int32 diff);
+  void on_pending_notification_update_count_changed(int32 diff, int32 notification_group_id, const char *source);
 
   NotificationId current_notification_id_;
   NotificationGroupId current_notification_group_id_;