diff --git a/intuitlib/utils.py b/intuitlib/utils.py
index 68dddac..1747250 100644
--- a/intuitlib/utils.py
+++ b/intuitlib/utils.py
@@ -84,7 +84,7 @@ def send_request(method, url, header, obj, body=None, session=None, oauth1_heade
     :return: requests object
     """
 
-    headers = ACCEPT_HEADER
+    headers = ACCEPT_HEADER.copy()
     header.update(headers)
 
     if session is not None and isinstance(session, Session):
diff --git a/tests/test_client.py b/tests/test_client.py
index 5ebc106..99cda29 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -25,6 +25,7 @@
     from urlparse import urlparse, parse_qs, urlsplit
 
 from intuitlib.enums import Scopes
+from intuitlib.config import ACCEPT_HEADER
 from intuitlib.client import AuthClient
 from intuitlib.exceptions import AuthClientError
 from tests.helper import MockResponse
@@ -91,12 +92,17 @@ def test_exceptions_all_bad_request(self, mock_post):
     
     @mock.patch('intuitlib.utils.requests.Session.request')
     def test_get_user_info_ok(self, mock_session):
+
+        header_before_call = ACCEPT_HEADER.copy()
+
         mock_resp = self.mock_request(status=200, content={
             'givenName': 'Test'
         })
         mock_session.return_value = mock_resp
         
         response = self.auth_client.get_user_info(access_token='token')
+        # verify that we didn't pollute the default headers used for subsequent calls.
+        assert header_before_call == ACCEPT_HEADER.copy()
         assert response.json()['givenName'] == 'Test'
 
     @mock.patch('intuitlib.utils.requests.Session.request')
@@ -108,4 +114,4 @@ def test_revoke_ok(self, mock_session):
         assert response
 
 if __name__ == '__main__':
-    pytest.main()
\ No newline at end of file
+    pytest.main()