diff --git a/jenkins/__init__.py b/jenkins/__init__.py
index 6236f4c..d9387d2 100755
--- a/jenkins/__init__.py
+++ b/jenkins/__init__.py
@@ -2136,9 +2136,14 @@ class Jenkins(object):
         folder_url, short_name = self._get_job_folder(folder_name)
         name = self._get_tag_text('id', config_xml)
         self.assert_credential_exists(name, folder_name, domain_name)
+
+        reconfig_url = self._build_url(CONFIG_CREDENTIAL, locals())
+
         self.jenkins_open(requests.Request(
-            'POST', self._build_url(CONFIG_CREDENTIAL, locals())
-            ))
+            'POST', reconfig_url,
+            data=config_xml.encode('utf-8'),
+            headers=DEFAULT_HEADERS
+        ))
 
     def list_credentials(self, folder_name, domain_name='_'):
         '''List credentials in domain of folder
diff --git a/tests/test_credential.py b/tests/test_credential.py
index 8e4e5f7..8e7418b 100644
--- a/tests/test_credential.py
+++ b/tests/test_credential.py
@@ -332,6 +332,10 @@ class JenkinsReconfigCredentialTest(JenkinsCredentialTestBase):
             jenkins_mock.call_args_list[2][0][0].url,
             self.make_url('job/Test%20Folder/credentials/store/folder/domain/'
                           '_/credential/Test%20Credential/config.xml'))
+        self.assertEqual(
+            jenkins_mock.call_args_list[2][0][0].data,
+            self.config_xml.encode('utf-8'))
+
         self._check_requests(jenkins_mock.call_args_list)