diff --git a/td/telegram/MessageViewer.cpp b/td/telegram/MessageViewer.cpp
index 3628a813d..b7aee7c1b 100644
--- a/td/telegram/MessageViewer.cpp
+++ b/td/telegram/MessageViewer.cpp
@@ -45,11 +45,15 @@ MessageViewers::MessageViewers(vector<telegram_api::object_ptr<telegram_api::sto
   }
 }
 
-MessageViewers::MessageViewers(vector<telegram_api::object_ptr<telegram_api::readParticipantDate>> &&read_dates)
-    : message_viewers_(
-          transform(std::move(read_dates), [](telegram_api::object_ptr<telegram_api::readParticipantDate> &&read_date) {
-            return MessageViewer(std::move(read_date));
-          })) {
+MessageViewers::MessageViewers(vector<telegram_api::object_ptr<telegram_api::readParticipantDate>> &&read_dates) {
+  for (auto &read_date : read_dates) {
+    message_viewers_.emplace_back(std::move(read_date));
+    auto user_id = message_viewers_.back().get_user_id();
+    if (!user_id.is_valid()) {
+      LOG(ERROR) << "Receive invalid " << user_id << " as a viewer of a message";
+      message_viewers_.pop_back();
+    }
+  }
 }
 
 MessageViewers MessageViewers::get_sublist(const MessageViewer &offset, int32 limit) const {
diff --git a/td/telegram/MessagesManager.cpp b/td/telegram/MessagesManager.cpp
index 85f355150..86bcf1296 100644
--- a/td/telegram/MessagesManager.cpp
+++ b/td/telegram/MessagesManager.cpp
@@ -18201,10 +18201,6 @@ void MessagesManager::on_get_message_viewers(DialogId dialog_id, MessageViewers
   if (!is_recursive) {
     bool need_participant_list = false;
     for (auto user_id : message_viewers.get_user_ids()) {
-      if (!user_id.is_valid()) {
-        LOG(ERROR) << "Receive invalid " << user_id << " as viewer of a message in " << dialog_id;
-        continue;
-      }
       if (!td_->contacts_manager_->have_user_force(user_id)) {
         need_participant_list = true;
       }