diff --git a/td/telegram/Global.cpp b/td/telegram/Global.cpp
index d5417e88..c3421dae 100644
--- a/td/telegram/Global.cpp
+++ b/td/telegram/Global.cpp
@@ -102,6 +102,9 @@ Status Global::init(const TdParameters &parameters, ActorId<Td> td, unique_ptr<T
     ServerTimeDiff saved_diff;
     unserialize(saved_diff, saved_diff_str).ensure();
 
+    saved_diff_ = saved_diff.diff;
+    saved_system_time_ = saved_diff.system_time;
+
     double diff = saved_diff.diff + default_time_difference;
     if (saved_diff.system_time > system_time) {
       double time_backwards_fix = saved_diff.system_time - system_time;
@@ -129,8 +132,9 @@ Status Global::init(const TdParameters &parameters, ActorId<Td> td, unique_ptr<T
   return Status::OK();
 }
 
-int32 Global::to_unix_time(double server_time) {
-  LOG_CHECK(1.0 <= server_time && server_time <= 2140000000.0) << server_time << " " << Clocks::system();
+int32 Global::to_unix_time(double server_time) const {
+  LOG_CHECK(1.0 <= server_time && server_time <= 2140000000.0)
+      << server_time << " " << Clocks::system() << " " << saved_diff_ << " " << saved_system_time_;
   return static_cast<int32>(server_time);
 }
 
diff --git a/td/telegram/Global.h b/td/telegram/Global.h
index 9cfc0f3e..6fbf7223 100644
--- a/td/telegram/Global.h
+++ b/td/telegram/Global.h
@@ -398,6 +398,8 @@ class Global : public ActorContext {
   std::atomic<bool> dns_time_difference_was_updated_{false};
   std::atomic<bool> close_flag_{false};
   std::atomic<double> system_time_saved_at_{-1e10};
+  double saved_diff_ = 0.0;
+  double saved_system_time_ = 0.0;
 
 #if !TD_HAVE_ATOMIC_SHARED_PTR
   std::mutex dh_config_mutex_;
@@ -418,7 +420,7 @@ class Global : public ActorContext {
 
   std::unordered_map<int64, int64> location_access_hashes_;
 
-  static int32 to_unix_time(double server_time);
+  int32 to_unix_time(double server_time) const;
 
   void do_save_server_time_difference();