diff --git a/CHANGELOG.md b/CHANGELOG.md
index b4286db..934f3fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,6 +27,8 @@ This update accompanies the release of the [Telegram Bot API 6.6](https://core.t
  * Added abstract class `\TgBotLib\Abstracts > StickerFormat` to represent a sticker format ("`static`", "`animated`" or "`video`")
  * Added method `\TgBotLib\Bot > uploadStickerFile()` to upload a sticker file with a sticker for later use in `createNewStickerSet` and `addStickerToSet` methods (can be used multiple times). 
    See [uploadStickerFile](https://core.telegram.org/bots/api#uploadstickerfile) for more information.
+ * Added method `\TgBotLib\Bot > setCustomEmojiStickerSetThumbnail()` to set the thumbnail of a sticker set. 
+   See [setCustomEmojiStickerSetThumbnail](https://core.telegram.org/bots/api#setcustomemojistickersetthumbnail) for more information.
 
 ### Changed
  * Removed unused `__destruct()` method from `\TgBotLib\Bot`
diff --git a/src/TgBotLib/Bot.php b/src/TgBotLib/Bot.php
index 01ee53d..f2f4847 100644
--- a/src/TgBotLib/Bot.php
+++ b/src/TgBotLib/Bot.php
@@ -2573,4 +2573,24 @@
             unset($tmp_file);
             return $response;
         }
+
+        /**
+         * Use this method to set the thumbnail of a custom emoji sticker set. Returns True on success.
+         *
+         * @param string $name Sticker set name
+         * @param string $custom_emoji_id Custom emoji identifier of a sticker from the sticker set; pass an empty string to drop the thumbnail and use the first sticker as the thumbnail.
+         * @return bool
+         * @throws TelegramException
+         * @link https://core.telegram.org/bots/api#setcustomemojistickersetthumbnail
+         * @noinspection PhpUnused
+         */
+        public function setCustomEmojiStickerSetThumbnail(string $name, string $custom_emoji_id=''): bool
+        {
+            $this->sendRequest('setCustomEmojiStickerSetThumbnail', [
+                'name' => $name,
+                'custom_emoji_id' => $custom_emoji_id
+            ]);
+
+            return true;
+        }
     }
\ No newline at end of file