diff --git a/kallithea/tests/functional/test_files.py b/kallithea/tests/functional/test_files.py
--- a/kallithea/tests/functional/test_files.py
+++ b/kallithea/tests/functional/test_files.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 import os
 import posixpath
+import mimetypes
 from kallithea.tests import *
 from kallithea.model.db import Repository
 from kallithea.model.meta import Session
@@ -242,7 +243,7 @@ removed extra unicode conversion in diff
                                     f_path='vcs/nodes.py'))
 
         self.assertEqual(response.content_disposition, "attachment; filename=nodes.py")
-        self.assertEqual(response.content_type, "text/x-python")
+        self.assertEqual(response.content_type, mimetypes.guess_type("nodes.py")[0])
 
     def test_raw_file_wrong_cs(self):
         self.log_user()
diff --git a/kallithea/tests/vcs/test_nodes.py b/kallithea/tests/vcs/test_nodes.py
--- a/kallithea/tests/vcs/test_nodes.py
+++ b/kallithea/tests/vcs/test_nodes.py
@@ -1,5 +1,6 @@
 
 import stat
+import mimetypes
 from kallithea.lib.vcs.nodes import DirNode
 from kallithea.lib.vcs.nodes import FileNode
 from kallithea.lib.vcs.nodes import Node
@@ -159,11 +160,11 @@ class NodeBasicTest(unittest.TestCase):
         my_node3 = FileNode('myfile3')
         my_node3._mimetype = [ext,ext]
 
-        self.assertEqual(py_node.mimetype,'text/x-python')
-        self.assertEqual(py_node.get_mimetype(),('text/x-python',None))
+        self.assertEqual(py_node.mimetype, mimetypes.guess_type(py_node.name)[0])
+        self.assertEqual(py_node.get_mimetype(), mimetypes.guess_type(py_node.name))
 
-        self.assertEqual(tar_node.mimetype,'application/x-tar')
-        self.assertEqual(tar_node.get_mimetype(),('application/x-tar','gzip'))
+        self.assertEqual(tar_node.mimetype, mimetypes.guess_type(tar_node.name)[0])
+        self.assertEqual(tar_node.get_mimetype(), mimetypes.guess_type(tar_node.name))
 
         self.assertRaises(NodeError,my_node2.get_mimetype)