diff --git a/td/generate/scheme/td_api.tl b/td/generate/scheme/td_api.tl
index 4ece67ac1..5517acb86 100644
--- a/td/generate/scheme/td_api.tl
+++ b/td/generate/scheme/td_api.tl
@@ -7993,17 +7993,17 @@ checkStickerSetName name:string = CheckStickerSetNameResult;
 createNewStickerSet user_id:int53 title:string name:string sticker_format:StickerFormat sticker_type:StickerType needs_repainting:Bool stickers:vector<inputSticker> source:string = StickerSet;
 
 
-//@description Adds a new sticker to a set; for bots only. Returns the sticker set
+//@description Adds a new sticker to a set; for bots only
 //@user_id Sticker set owner
 //@name Sticker set name
 //@sticker Sticker to add to the set
 addStickerToSet user_id:int53 name:string sticker:inputSticker = Ok;
 
-//@description Sets a sticker set thumbnail; for bots only. Returns the sticker set
+//@description Sets a sticker set thumbnail; for bots only
 //@user_id Sticker set owner
 //@name Sticker set name
 //@thumbnail Thumbnail to set in PNG, TGS, or WEBM format; pass null to remove the sticker set thumbnail. Thumbnail format must match the format of stickers in the set
-setStickerSetThumbnail user_id:int53 name:string thumbnail:InputFile = StickerSet;
+setStickerSetThumbnail user_id:int53 name:string thumbnail:InputFile = Ok;
 
 //@description Sets a custom emoji sticker set thumbnail; for bots only
 //@name Sticker set name
diff --git a/td/telegram/StickersManager.cpp b/td/telegram/StickersManager.cpp
index 61b32a9e5..1d1ff844c 100644
--- a/td/telegram/StickersManager.cpp
+++ b/td/telegram/StickersManager.cpp
@@ -1219,11 +1219,10 @@ class AddStickerToSetQuery final : public Td::ResultHandler {
 };
 
 class SetStickerSetThumbnailQuery final : public Td::ResultHandler {
-  Promise<td_api::object_ptr<td_api::stickerSet>> promise_;
+  Promise<Unit> promise_;
 
  public:
-  explicit SetStickerSetThumbnailQuery(Promise<td_api::object_ptr<td_api::stickerSet>> &&promise)
-      : promise_(std::move(promise)) {
+  explicit SetStickerSetThumbnailQuery(Promise<Unit> &&promise) : promise_(std::move(promise)) {
   }
 
   void send(const string &short_name, tl_object_ptr<telegram_api::InputDocument> &&input_document) {
@@ -1245,7 +1244,7 @@ class SetStickerSetThumbnailQuery final : public Td::ResultHandler {
     if (!sticker_set_id.is_valid()) {
       return on_error(Status::Error(500, "Sticker set not found"));
     }
-    promise_.set_value(td_->stickers_manager_->get_sticker_set_object(sticker_set_id));
+    promise_.set_value(Unit());
   }
 
   void on_error(Status status) final {
@@ -8541,8 +8540,7 @@ void StickersManager::on_added_sticker_uploaded(int64 random_id, Result<Unit> re
 }
 
 void StickersManager::set_sticker_set_thumbnail(UserId user_id, string short_name,
-                                                tl_object_ptr<td_api::InputFile> &&thumbnail,
-                                                Promise<td_api::object_ptr<td_api::stickerSet>> &&promise) {
+                                                tl_object_ptr<td_api::InputFile> &&thumbnail, Promise<Unit> &&promise) {
   TRY_RESULT_PROMISE(promise, input_user, td_->contacts_manager_->get_input_user(user_id));
 
   short_name = clean_username(strip_empty_characters(short_name, MAX_STICKER_SET_SHORT_NAME_LENGTH));
@@ -8571,7 +8569,7 @@ void StickersManager::set_sticker_set_thumbnail(UserId user_id, string short_nam
 
 void StickersManager::do_set_sticker_set_thumbnail(UserId user_id, string short_name,
                                                    tl_object_ptr<td_api::InputFile> &&thumbnail,
-                                                   Promise<td_api::object_ptr<td_api::stickerSet>> &&promise) {
+                                                   Promise<Unit> &&promise) {
   TRY_STATUS_PROMISE(promise, G()->close_status());
 
   const StickerSet *sticker_set = get_sticker_set(short_name_to_sticker_set_id_.get(short_name));
diff --git a/td/telegram/StickersManager.h b/td/telegram/StickersManager.h
index 6a002bca0..ead1088f6 100644
--- a/td/telegram/StickersManager.h
+++ b/td/telegram/StickersManager.h
@@ -309,7 +309,7 @@ class StickersManager final : public Actor {
                           Promise<Unit> &&promise);
 
   void set_sticker_set_thumbnail(UserId user_id, string short_name, tl_object_ptr<td_api::InputFile> &&thumbnail,
-                                 Promise<td_api::object_ptr<td_api::stickerSet>> &&promise);
+                                 Promise<Unit> &&promise);
 
   void set_custom_emoji_sticker_set_thumbnail(string short_name, CustomEmojiId custom_emoji_id,
                                               Promise<Unit> &&promise);
@@ -546,7 +546,7 @@ class StickersManager final : public Actor {
   struct PendingSetStickerSetThumbnail {
     string short_name_;
     FileId file_id_;
-    Promise<td_api::object_ptr<td_api::stickerSet>> promise_;
+    Promise<Unit> promise_;
   };
 
   struct PendingGetAnimatedEmojiClickSticker {
@@ -880,7 +880,7 @@ class StickersManager final : public Actor {
   void on_sticker_set_thumbnail_uploaded(int64 random_id, Result<Unit> result);
 
   void do_set_sticker_set_thumbnail(UserId user_id, string short_name, tl_object_ptr<td_api::InputFile> &&thumbnail,
-                                    Promise<td_api::object_ptr<td_api::stickerSet>> &&promise);
+                                    Promise<Unit> &&promise);
 
   void do_set_custom_emoji_sticker_set_thumbnail(string short_name, CustomEmojiId custom_emoji_id,
                                                  Promise<Unit> &&promise);
diff --git a/td/telegram/Td.cpp b/td/telegram/Td.cpp
index 13f8e4fbf..06e01e027 100644
--- a/td/telegram/Td.cpp
+++ b/td/telegram/Td.cpp
@@ -7303,7 +7303,7 @@ void Td::on_request(uint64 id, td_api::addStickerToSet &request) {
 void Td::on_request(uint64 id, td_api::setStickerSetThumbnail &request) {
   CHECK_IS_BOT();
   CLEAN_INPUT_STRING(request.name_);
-  CREATE_REQUEST_PROMISE();
+  CREATE_OK_REQUEST_PROMISE();
   stickers_manager_->set_sticker_set_thumbnail(UserId(request.user_id_), std::move(request.name_),
                                                std::move(request.thumbnail_), std::move(promise));
 }