diff --git a/tests/test_video.py b/tests/test_video.py
index facd8d263..a704c5279 100644
--- a/tests/test_video.py
+++ b/tests/test_video.py
@@ -81,7 +81,7 @@ class VideoTest(BaseTest, unittest.TestCase):
         self.assertEqual(video.height, self.height)
         self.assertEqual(video.duration, self.duration)
         self.assertEqual(video.thumb, self.thumb)
-        self.assertEqual(video.mime_type, None)
+        self.assertEqual(video.mime_type, 'video/mp4')
         self.assertEqual(video.file_size, self.file_size)
 
     @flaky(3, 1)
@@ -102,7 +102,7 @@ class VideoTest(BaseTest, unittest.TestCase):
         self.assertEqual(video.height, self.height)
         self.assertEqual(video.duration, self.duration)
         self.assertEqual(video.thumb, self.thumb)
-        self.assertEqual(video.mime_type, None)
+        self.assertEqual(video.mime_type, 'video/mp4')
         self.assertEqual(video.file_size, self.file_size)
 
         self.assertEqual(message.caption, self.caption)
@@ -125,7 +125,7 @@ class VideoTest(BaseTest, unittest.TestCase):
         self.assertEqual(video.height, self.height)
         self.assertEqual(video.duration, self.duration)
         self.assertEqual(video.thumb, self.thumb)
-        self.assertEqual(video.mime_type, None)
+        self.assertEqual(video.mime_type, 'video/mp4')
         self.assertEqual(video.file_size, self.file_size)
 
         self.assertEqual(message.caption, self.caption)
@@ -149,7 +149,7 @@ class VideoTest(BaseTest, unittest.TestCase):
         self.assertEqual(video.height, self.height)
         self.assertEqual(video.duration, self.duration)
         self.assertEqual(video.thumb, self.thumb)
-        self.assertEqual(video.mime_type, None)
+        self.assertEqual(video.mime_type, 'video/mp4')
         self.assertEqual(video.file_size, self.file_size)
 
         self.assertEqual(message.caption, self.caption)
@@ -171,7 +171,7 @@ class VideoTest(BaseTest, unittest.TestCase):
         self.assertEqual(video.height, self.height)
         self.assertEqual(video.duration, self.duration)
         self.assertEqual(video.thumb, self.thumb_from_url)
-        self.assertEqual(video.mime_type, None)
+        self.assertEqual(video.mime_type, 'video/mp4')
         self.assertEqual(video.file_size, self.file_size)
 
         self.assertEqual(message.caption, self.caption)
@@ -191,7 +191,7 @@ class VideoTest(BaseTest, unittest.TestCase):
         self.assertEqual(video.file_id, self.video_file_id)
         self.assertEqual(video.duration, 0)
         self.assertEqual(video.thumb, None)
-        self.assertEqual(video.mime_type, None)
+        self.assertEqual(video.mime_type, 'video/mp4')
 
         self.assertEqual(message.caption, self.caption)