diff --git a/telegram/ext/updater.py b/telegram/ext/updater.py
index 5339bdcb3..219c122c9 100644
--- a/telegram/ext/updater.py
+++ b/telegram/ext/updater.py
@@ -260,7 +260,7 @@ class Updater(object):
                 return self.update_queue
 
     def _start_polling(self, poll_interval, timeout, read_latency, bootstrap_retries, clean,
-                       allowed_updates):
+                       allowed_updates):  # pragma: no cover
         # """
         # Thread target of thread 'updater'. Runs in background, pulls
         # updates from Telegram and inserts them in the update queue of the
diff --git a/telegram/utils/request.py b/telegram/utils/request.py
index 154fa691b..a5d770541 100644
--- a/telegram/utils/request.py
+++ b/telegram/utils/request.py
@@ -29,6 +29,7 @@ except ImportError:
     import json
 
 import certifi
+
 try:
     import telegram.vendor.ptb_urllib3.urllib3 as urllib3
     import telegram.vendor.ptb_urllib3.urllib3.contrib.appengine as appengine
@@ -150,7 +151,7 @@ class Request(object):
         except ValueError:
             raise TelegramError('Invalid server response')
 
-        if not data.get('ok'):
+        if not data.get('ok'):  # pragma: no cover
             description = data.get('description')
             parameters = data.get('parameters')
             if parameters:
diff --git a/tests/test_error.py b/tests/test_error.py
new file mode 100644
index 000000000..0bdc67cd2
--- /dev/null
+++ b/tests/test_error.py
@@ -0,0 +1,85 @@
+#!/usr/bin/env python
+#
+# A library that provides a Python interface to the Telegram Bot API
+# Copyright (C) 2015-2017
+# Leandro Toledo de Souza <devs@python-telegram-bot.org>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser Public License for more details.
+#
+# You should have received a copy of the GNU Lesser Public License
+# along with this program.  If not, see [http://www.gnu.org/licenses/].
+import pytest
+
+from telegram import TelegramError
+from telegram.error import Unauthorized, InvalidToken, NetworkError, BadRequest, TimedOut, \
+    ChatMigrated, RetryAfter
+
+
+class TestErrors(object):
+    def test_telegram_error(self):
+        with pytest.raises(TelegramError, match="^test message$"):
+            raise TelegramError("test message")
+        with pytest.raises(TelegramError, match="^Test message$"):
+            raise TelegramError("Error: test message")
+        with pytest.raises(TelegramError, match="^Test message$"):
+            raise TelegramError("[Error]: test message")
+        with pytest.raises(TelegramError, match="^Test message$"):
+            raise TelegramError("Bad Request: test message")
+
+    def test_unauthorized(self):
+        with pytest.raises(Unauthorized, match="test message"):
+            raise Unauthorized("test message")
+        with pytest.raises(Unauthorized, match="^Test message$"):
+            raise Unauthorized("Error: test message")
+        with pytest.raises(Unauthorized, match="^Test message$"):
+            raise Unauthorized("[Error]: test message")
+        with pytest.raises(Unauthorized, match="^Test message$"):
+            raise Unauthorized("Bad Request: test message")
+
+    def test_invalid_token(self):
+        with pytest.raises(InvalidToken, match="Invalid token"):
+            raise InvalidToken
+
+    def test_network_error(self):
+        with pytest.raises(NetworkError, match="test message"):
+            raise NetworkError("test message")
+        with pytest.raises(NetworkError, match="^Test message$"):
+            raise NetworkError("Error: test message")
+        with pytest.raises(NetworkError, match="^Test message$"):
+            raise NetworkError("[Error]: test message")
+        with pytest.raises(NetworkError, match="^Test message$"):
+            raise NetworkError("Bad Request: test message")
+
+    def test_bad_request(self):
+        with pytest.raises(BadRequest, match="test message"):
+            raise BadRequest("test message")
+        with pytest.raises(BadRequest, match="^Test message$"):
+            raise BadRequest("Error: test message")
+        with pytest.raises(BadRequest, match="^Test message$"):
+            raise BadRequest("[Error]: test message")
+        with pytest.raises(BadRequest, match="^Test message$"):
+            raise BadRequest("Bad Request: test message")
+
+    def test_timed_out(self):
+        with pytest.raises(TimedOut, match="^Timed out$"):
+            raise TimedOut
+
+    def test_chat_migrated(self):
+        with pytest.raises(ChatMigrated, match="Group migrated to supergroup. New chat id: 1234"):
+            raise ChatMigrated(1234)
+        try:
+            raise ChatMigrated(1234)
+        except ChatMigrated as e:
+            assert e.new_chat_id == 1234
+
+    def test_retry_after(self):
+        with pytest.raises(RetryAfter, match="Flood control exceeded. Retry in 12 seconds"):
+            raise RetryAfter(12)