diff --git a/telegram/utils/request.py b/telegram/utils/request.py
index 28cca9e41..ec7b8cdc5 100644
--- a/telegram/utils/request.py
+++ b/telegram/utils/request.py
@@ -29,6 +29,7 @@ from telegram import (InputFile, TelegramError)
 from telegram.error import Unauthorized, NetworkError, TimedOut, BadRequest
 
 _CON_POOL = None
+""":type: urllib3.HTTPSConnectionPool"""
 CON_POOL_SIZE = 1