diff --git a/td/telegram/AuthManager.cpp b/td/telegram/AuthManager.cpp
index b47a9f948..78e5e0593 100644
--- a/td/telegram/AuthManager.cpp
+++ b/td/telegram/AuthManager.cpp
@@ -1121,28 +1121,8 @@ bool AuthManager::load_state() {
     LOG(INFO) << "Ignore auth_state: api_id or api_hash changed";
     return false;
   }
-  if (!db_state.state_timestamp_.is_in_past()) {
-    LOG(INFO) << "Ignore auth_state: timestamp in the future";
-    return false;
-  }
-  auto state_timeout = [state = db_state.state_] {
-    switch (state) {
-      case State::WaitPassword:
-      case State::WaitRegistration:
-        return 86400;
-      case State::WaitEmailAddress:
-      case State::WaitEmailCode:
-      case State::WaitCode:
-      case State::WaitQrCodeConfirmation:
-        return 5 * 60;
-      default:
-        UNREACHABLE();
-        return 0;
-    }
-  }();
-
-  if (Timestamp::at(db_state.state_timestamp_.at() + state_timeout).is_in_past()) {
-    LOG(INFO) << "Ignore auth_state: expired " << db_state.state_timestamp_.in();
+  if (db_state.expires_at_ <= Time::now()) {
+    LOG(INFO) << "Ignore auth_state: expired";
     return false;
   }
 
diff --git a/td/telegram/AuthManager.h b/td/telegram/AuthManager.h
index d6aeef3c3..0ae4d2d16 100644
--- a/td/telegram/AuthManager.h
+++ b/td/telegram/AuthManager.h
@@ -117,7 +117,7 @@ class AuthManager final : public NetActor {
     State state_;
     int32 api_id_;
     string api_hash_;
-    Timestamp state_timestamp_;
+    double expires_at_;
 
     // WaitEmailAddress and WaitEmailCode
     bool allow_apple_id_ = false;
@@ -202,7 +202,23 @@ class AuthManager final : public NetActor {
 
    private:
     DbState(State state, int32 api_id, string &&api_hash)
-        : state_(state), api_id_(api_id), api_hash_(std::move(api_hash)), state_timestamp_(Timestamp::now()) {
+        : state_(state), api_id_(api_id), api_hash_(std::move(api_hash)) {
+      auto state_timeout = [state] {
+        switch (state) {
+          case State::WaitPassword:
+          case State::WaitRegistration:
+            return 86400;
+          case State::WaitEmailAddress:
+          case State::WaitEmailCode:
+          case State::WaitCode:
+          case State::WaitQrCodeConfirmation:
+            return 5 * 60;
+          default:
+            UNREACHABLE();
+            return 0;
+        }
+      }();
+      expires_at_ = Time::now() + state_timeout;
     }
   };
 
diff --git a/td/telegram/AuthManager.hpp b/td/telegram/AuthManager.hpp
index 65225376e..c6cf496d1 100644
--- a/td/telegram/AuthManager.hpp
+++ b/td/telegram/AuthManager.hpp
@@ -70,7 +70,7 @@ void AuthManager::DbState::store(StorerT &storer) const {
   store(state_, storer);
   store(api_id_, storer);
   store(api_hash_, storer);
-  store_time(state_timestamp_.at(), storer);
+  store_time(expires_at_, storer);
 
   if (has_terms_of_service) {
     store(terms_of_service_, storer);
@@ -133,9 +133,7 @@ void AuthManager::DbState::parse(ParserT &parser) {
   parse(state_, parser);
   parse(api_id_, parser);
   parse(api_hash_, parser);
-  double state_timestamp = 0.0;
-  parse_time(state_timestamp, parser);
-  state_timestamp_ = Timestamp::at(state_timestamp);
+  parse_time(expires_at_, parser);
 
   if (has_terms_of_service) {
     parse(terms_of_service_, parser);