diff --git a/swiftclient/client.py b/swiftclient/client.py
index 80b6eda2..80bc4a3a 100644
--- a/swiftclient/client.py
+++ b/swiftclient/client.py
@@ -1286,8 +1286,10 @@ def put_object(url, token=None, container=None, name=None, contents=None,
     if content_type is not None:
         headers['Content-Type'] = content_type
     elif 'Content-Type' not in headers:
-        # python-requests sets application/x-www-form-urlencoded otherwise
-        headers['Content-Type'] = ''
+        if StrictVersion(requests.__version__) < StrictVersion('2.4.0'):
+            # python-requests sets application/x-www-form-urlencoded otherwise
+            # if using python3.
+            headers['Content-Type'] = ''
     if not contents:
         headers['Content-Length'] = '0'
 
diff --git a/tests/unit/test_swiftclient.py b/tests/unit/test_swiftclient.py
index 2cd5cf15..5384ac7f 100644
--- a/tests/unit/test_swiftclient.py
+++ b/tests/unit/test_swiftclient.py
@@ -1163,6 +1163,7 @@ class TestHeadObject(MockHttpTest):
 
 class TestPutObject(MockHttpTest):
 
+    @mock.patch('swiftclient.requests.__version__', '2.2.0')
     def test_ok(self):
         c.http_connection = self.fake_http_connection(200)
         args = ('http://www.test.com', 'TOKEN', 'container', 'obj', 'body', 4)
@@ -1220,6 +1221,7 @@ class TestPutObject(MockHttpTest):
             self.assertEqual(len(w), 1)
             self.assertTrue(issubclass(w[-1].category, UserWarning))
 
+    @mock.patch('swiftclient.requests.__version__', '2.2.0')
     def test_server_error(self):
         body = 'c' * 60
         headers = {'foo': 'bar'}
@@ -1234,7 +1236,8 @@ class TestPutObject(MockHttpTest):
         self.assertEqual(e.http_status, 500)
         self.assertRequests([
             ('PUT', '/asdf/asdf', 'asdf', {
-                'x-auth-token': 'asdf', 'content-type': ''}),
+                'x-auth-token': 'asdf',
+                'content-type': ''}),
         ])
 
     def test_query_string(self):
@@ -1375,7 +1378,8 @@ class TestPutObject(MockHttpTest):
         self.assertEqual(request_header['etag'], b'1234-5678')
         self.assertEqual(request_header['content-type'], b'text/plain')
 
-    def test_no_content_type(self):
+    @mock.patch('swiftclient.requests.__version__', '2.2.0')
+    def test_no_content_type_old_requests(self):
         conn = c.http_connection(u'http://www.test.com/')
         resp = MockHttpResponse(status=200)
         conn[1].getresponse = resp.fake_response
@@ -1385,6 +1389,17 @@ class TestPutObject(MockHttpTest):
         request_header = resp.requests_params['headers']
         self.assertEqual(request_header['content-type'], b'')
 
+    @mock.patch('swiftclient.requests.__version__', '2.4.0')
+    def test_no_content_type_new_requests(self):
+        conn = c.http_connection(u'http://www.test.com/')
+        resp = MockHttpResponse(status=200)
+        conn[1].getresponse = resp.fake_response
+        conn[1]._request = resp._fake_request
+
+        c.put_object(url='http://www.test.com', http_conn=conn)
+        request_header = resp.requests_params['headers']
+        self.assertNotIn('content-type', request_header)
+
     def test_content_type_in_headers(self):
         conn = c.http_connection(u'http://www.test.com/')
         resp = MockHttpResponse(status=200)