diff --git a/tests/test_filters.py b/tests/test_filters.py
index 674042de1..0911d0667 100644
--- a/tests/test_filters.py
+++ b/tests/test_filters.py
@@ -214,18 +214,43 @@ class FiltersTest(BaseTest, unittest.TestCase):
         self.assertTrue(Filters.group(self.message))
 
     def test_filters_chat(self):
-        self.assertFalse(Filters.chat(-1)(self.message))
+        with self.assertRaisesRegexp(ValueError, 'either chat_id or username'):
+            Filters.chat(chat_id=0, username='chat')
+            Filters.chat()
+
+    def test_filters_chat_id(self):
+        self.assertFalse(Filters.chat(chat_id=-1)(self.message))
         self.message.chat.id = -1
-        self.assertTrue(Filters.chat(-1)(self.message))
+        self.assertTrue(Filters.chat(chat_id=-1)(self.message))
         self.message.chat.id = -2
-        self.assertFalse(Filters.chat(-1)(self.message))
+        self.assertFalse(Filters.chat(chat_id=-1)(self.message))
+
+    def test_filters_chat_username(self):
+        self.assertFalse(Filters.chat(username='chat')(self.message))
+        self.message.chat.username = 'chat'
+        self.assertTrue(Filters.chat(username='@chat')(self.message))
+        self.assertTrue(Filters.chat(username='chat')(self.message))
+        self.assertFalse(Filters.chat(username='@chat_username')(self.message))
 
     def test_filters_user(self):
-        self.assertFalse(Filters.user(1)(self.message))
+        with self.assertRaisesRegexp(ValueError, 'either user_id or username'):
+            Filters.user(user_id=0, username='user')
+            Filters.user()
+
+    def test_filters_user_id(self):
+        self.assertFalse(Filters.user(user_id=1)(self.message))
         self.message.from_user.id = 1
-        self.assertTrue(Filters.user(1)(self.message))
+        self.assertTrue(Filters.user(user_id=1)(self.message))
         self.message.from_user.id = 2
-        self.assertFalse(Filters.user(1)(self.message))
+        self.assertFalse(Filters.user(user_id=1)(self.message))
+
+    def test_filters_username(self):
+        self.assertFalse(Filters.user(username='user')(self.message))
+        self.assertFalse(Filters.user(username='Testuser')(self.message))
+        self.message.from_user.username = 'user'
+        self.assertTrue(Filters.user(username='@user')(self.message))
+        self.assertTrue(Filters.user(username='user')(self.message))
+        self.assertFalse(Filters.user(username='@username')(self.message))
 
     def test_and_filters(self):
         self.message.text = 'test'