diff --git a/requirements.txt b/requirements.txt
index 9e7a55731..678e22607 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 future
 urllib3
+certifi
diff --git a/telegram/utils/request.py b/telegram/utils/request.py
index 8600f5c31..5926add9f 100644
--- a/telegram/utils/request.py
+++ b/telegram/utils/request.py
@@ -20,6 +20,7 @@
 
 import json
 
+import certifi
 import urllib3
 
 from telegram import (InputFile, TelegramError)
@@ -33,7 +34,7 @@ def _get_con_pool():
         return _CON_POOL
 
     global _CON_POOL
-    _CON_POOL = urllib3.PoolManager(10)
+    _CON_POOL = urllib3.PoolManager(10, cert_reqs='CERT_REQUIRED', ca_certs=certifi.where())
     return _CON_POOL