diff --git a/td/telegram/ContactsManager.cpp b/td/telegram/ContactsManager.cpp
index 8c7896b5..d8a0682c 100644
--- a/td/telegram/ContactsManager.cpp
+++ b/td/telegram/ContactsManager.cpp
@@ -1395,7 +1395,15 @@ class ToggleSlowModeQuery : public Td::ResultHandler {
   }
 
   void on_error(uint64 id, Status status) override {
-    td->contacts_manager_->on_get_channel_error(channel_id_, status, "ToggleSlowModeQuery");
+    if (status.message() == "CHAT_NOT_MODIFIED") {
+      td->contacts_manager_->on_update_channel_slow_mode_delay(channel_id_, slow_mode_delay_);
+      if (!td->auth_manager_->is_bot()) {
+        promise_.set_value(Unit());
+        return;
+      }
+    } else {
+      td->contacts_manager_->on_get_channel_error(channel_id_, status, "ToggleSlowModeQuery");
+    }
     promise_.set_error(std::move(status));
   }
 };
@@ -9760,7 +9768,7 @@ void ContactsManager::on_update_channel_full_slow_mode_delay(ChannelFull *channe
   Channel *c = get_channel(channel_id);
   CHECK(c != nullptr);
   bool is_slow_mode_enabled = slow_mode_delay != 0;
-  if (is_slow_mode_enabled == c->is_slow_mode_enabled) {
+  if (is_slow_mode_enabled != c->is_slow_mode_enabled) {
     c->is_slow_mode_enabled = is_slow_mode_enabled;
     c->is_changed = true;
     update_channel(c, channel_id);
diff --git a/td/telegram/MessagesManager.cpp b/td/telegram/MessagesManager.cpp
index 40130503..6ddee68c 100644
--- a/td/telegram/MessagesManager.cpp
+++ b/td/telegram/MessagesManager.cpp
@@ -24764,7 +24764,7 @@ MessagesManager::Message *MessagesManager::add_message_to_dialog(Dialog *d, uniq
     add_message_to_database(d, m, "add_message_to_dialog");
   }
 
-  if (*need_update && dialog_id.get_type() == DialogType::Channel) {
+  if (from_update && dialog_id.get_type() == DialogType::Channel) {
     auto now = max(G()->unix_time_cached(), m->date);
     if (m->date < now - 2 * 86400 && Slice(source) == Slice("updateNewChannelMessage")) {
       // if the message is pretty old, we might have missed the update that the message has already been read