diff --git a/td/telegram/Global.cpp b/td/telegram/Global.cpp
index 6ea02ded..348073cd 100644
--- a/td/telegram/Global.cpp
+++ b/td/telegram/Global.cpp
@@ -61,16 +61,16 @@ void Global::set_mtproto_header(unique_ptr<MtprotoHeader> mtproto_header) {
   mtproto_header_ = std::move(mtproto_header);
 }
 
-Status Global::init(const TdParameters &parameters, ActorId<Td> td, unique_ptr<TdDb> td_db) {
+Status Global::init(const TdParameters &parameters, ActorId<Td> td, unique_ptr<TdDb> td_db_ptr) {
   parameters_ = parameters;
 
   gc_scheduler_id_ = min(Scheduler::instance()->sched_id() + 2, Scheduler::instance()->sched_count() - 1);
   slow_net_scheduler_id_ = min(Scheduler::instance()->sched_id() + 3, Scheduler::instance()->sched_count() - 1);
 
   td_ = td;
-  td_db_ = std::move(td_db);
+  td_db_ = std::move(td_db_ptr);
 
-  string save_diff_str = this->td_db()->get_binlog_pmc()->get("server_time_difference");
+  string save_diff_str = td_db()->get_binlog_pmc()->get("server_time_difference");
   if (save_diff_str.empty()) {
     server_time_difference_ = Clocks::system() - Time::now();
     server_time_difference_was_updated_ = false;
diff --git a/td/telegram/Global.h b/td/telegram/Global.h
index 5314f06f..6a6dbab1 100644
--- a/td/telegram/Global.h
+++ b/td/telegram/Global.h
@@ -19,6 +19,7 @@
 #include "td/net/NetStats.h"
 
 #include "td/utils/common.h"
+#include "td/utils/logging.h"
 #include "td/utils/Slice.h"
 #include "td/utils/Status.h"
 #include "td/utils/Time.h"
@@ -67,14 +68,15 @@ class Global : public ActorContext {
   Global(Global &&other) = delete;
   Global &operator=(Global &&other) = delete;
 
-  TdDb *td_db() {
-    CHECK(td_db_);
+#define td_db() get_td_db_impl(__FILE__, __LINE__)
+  TdDb *get_td_db_impl(const char *file, int line) {
+    LOG_CHECK(td_db_) << close_flag() << " " << file << " " << line;
     return td_db_.get();
   }
   void close_all(Promise<> on_finished);
   void close_and_destroy_all(Promise<> on_finished);
 
-  Status init(const TdParameters &parameters, ActorId<Td> td, unique_ptr<TdDb> td_db) TD_WARN_UNUSED_RESULT;
+  Status init(const TdParameters &parameters, ActorId<Td> td, unique_ptr<TdDb> td_db_ptr) TD_WARN_UNUSED_RESULT;
 
   Slice get_dir() const {
     return parameters_.database_directory;