diff --git a/sendgrid/sendgrid.py b/sendgrid/sendgrid.py
index 61c664d88..3a4184027 100644
--- a/sendgrid/sendgrid.py
+++ b/sendgrid/sendgrid.py
@@ -26,7 +26,13 @@ def __init__(self, **opts):
         self.host = opts.get('host', 'https://api.sendgrid.com')
         self.version = __version__
 
+        headers = self._get_default_headers()
 
+        self.client = python_http_client.Client(host=self.host,
+                                                request_headers=headers,
+                                                version=3)
+
+    def _get_default_headers(self):
         headers = {
             "Authorization": 'Bearer {0}'.format(self._apikey),
             "User-agent": self.useragent,
@@ -35,9 +41,10 @@ def __init__(self, **opts):
         if self._impersonate_subuser:
             headers['On-Behalf-Of'] = self._impersonate_subuser
 
-        self.client = python_http_client.Client(host=self.host,
-                                                request_headers=headers,
-                                                version=3)
+        return headers
+
+    def reset_request_headers(self):
+        self.client.request_headers = self._get_default_headers()
 
     @property
     def apikey(self):
diff --git a/test/test_sendgrid.py b/test/test_sendgrid.py
index 1f16dcf2b..11331fbab 100644
--- a/test/test_sendgrid.py
+++ b/test/test_sendgrid.py
@@ -78,6 +78,37 @@ def test_useragent(self):
     def test_host(self):
         self.assertEqual(self.sg.host, self.host)
 
+    def test_get_default_headers(self):
+        headers = self.sg._get_default_headers()
+        self.assertIn('Authorization', headers)
+        self.assertIn('User-agent', headers)
+        self.assertIn('Accept', headers)
+        self.assertNotIn('On-Behalf-Of', headers)
+
+        self.sg._impersonate_subuser = 'ladida@testsubuser.sendgrid'
+        headers = self.sg._get_default_headers()
+        self.assertIn('Authorization', headers)
+        self.assertIn('User-agent', headers)
+        self.assertIn('Accept', headers)
+        self.assertIn('On-Behalf-Of', headers)
+
+    def test_reset_request_headers(self):
+        addl_headers = {
+            'blah': 'test value',
+            'blah2x': 'another test value',
+        }
+        self.sg.client.request_headers.update(addl_headers)
+        self.assertIn('blah', self.sg.client.request_headers)
+        self.assertIn('blah2x', self.sg.client.request_headers)
+
+        self.sg.reset_request_headers()
+        self.assertNotIn('blah', self.sg.client.request_headers)
+        self.assertNotIn('blah2x', self.sg.client.request_headers)
+
+        for k,v in self.sg._get_default_headers().items():
+            self.assertEqual(v, self.sg.client.request_headers[k])
+
+
     def test_access_settings_activity_get(self):
         params = {'limit': 1}
         headers = {'X-Mock': 200}