diff --git a/django/test/client.py b/django/test/client.py
index e5a16b6e79..498af5c344 100644
--- a/django/test/client.py
+++ b/django/test/client.py
@@ -3,6 +3,7 @@ from urlparse import urlparse, urlunparse, urlsplit
 import sys
 import os
 import re
+import mimetypes
 try:
     from cStringIO import StringIO
 except ImportError:
@@ -138,11 +139,14 @@ def encode_multipart(boundary, data):
 
 def encode_file(boundary, key, file):
     to_str = lambda s: smart_str(s, settings.DEFAULT_CHARSET)
+    content_type = mimetypes.guess_type(file.name)[0]
+    if content_type is None:
+        content_type = 'application/octet-stream'
     return [
         '--' + boundary,
         'Content-Disposition: form-data; name="%s"; filename="%s"' \
             % (to_str(key), to_str(os.path.basename(file.name))),
-        'Content-Type: application/octet-stream',
+        'Content-Type: %s' % content_type,
         '',
         file.read()
     ]
diff --git a/tests/regressiontests/test_client_regress/models.py b/tests/regressiontests/test_client_regress/models.py
index 7a564e9b69..cb8e1b3103 100644
--- a/tests/regressiontests/test_client_regress/models.py
+++ b/tests/regressiontests/test_client_regress/models.py
@@ -11,6 +11,7 @@ from django.core.urlresolvers import reverse
 from django.core.exceptions import SuspiciousOperation
 from django.template import TemplateDoesNotExist, TemplateSyntaxError, Context
 from django.template import loader
+from django.test.client import encode_file
 
 class AssertContainsTests(TestCase):
     def setUp(self):
@@ -823,3 +824,26 @@ class UnicodePayloadTests(TestCase):
         response = self.client.post("/test_client_regress/parse_unicode_json/", json,
                                     content_type="application/json; charset=koi8-r")
         self.assertEqual(response.content, json.encode('koi8-r'))
+
+class DummyFile(object):
+    def __init__(self, filename):
+        self.name = filename
+    def read(self):
+        return 'TEST_FILE_CONTENT'
+
+class UploadedFileEncodingTest(TestCase):
+    def test_file_encoding(self):
+        encoded_file = encode_file('TEST_BOUNDARY', 'TEST_KEY', DummyFile('test_name.bin'))
+        self.assertEqual('--TEST_BOUNDARY', encoded_file[0])
+        self.assertEqual('Content-Disposition: form-data; name="TEST_KEY"; filename="test_name.bin"', encoded_file[1])
+        self.assertEqual('TEST_FILE_CONTENT', encoded_file[-1])
+
+    def test_guesses_content_type_on_file_encoding(self):
+        self.assertEqual('Content-Type: application/octet-stream',
+                         encode_file('IGNORE', 'IGNORE', DummyFile("file.bin"))[2])
+        self.assertEqual('Content-Type: text/plain',
+                         encode_file('IGNORE', 'IGNORE', DummyFile("file.txt"))[2])
+        self.assertEqual('Content-Type: application/zip',
+                         encode_file('IGNORE', 'IGNORE', DummyFile("file.zip"))[2])
+        self.assertEqual('Content-Type: application/octet-stream',
+                         encode_file('IGNORE', 'IGNORE', DummyFile("file.unknown"))[2])