diff --git a/.travis.yml b/.travis.yml
index 295532d..dd89035 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,3 @@
-sudo: false
 language: python
 python:
     - "2.7"
@@ -8,4 +7,4 @@ python:
     - "3.8"
 install: "pip install ."
 script: "nosetests"
-dist: bionic
\ No newline at end of file
+dist: bionic
diff --git a/sickle/app.py b/sickle/app.py
index 6fa3b1b..86e3599 100644
--- a/sickle/app.py
+++ b/sickle/app.py
@@ -111,6 +111,7 @@ def __init__(self, endpoint,
         self.class_mapping = class_mapping or DEFAULT_CLASS_MAP
         self.encoding = encoding
         self.request_args = request_args
+        self.session = requests.Session()
 
     def harvest(self, **kwargs):  # pragma: no cover
         """Make HTTP requests to the OAI server.
@@ -134,8 +135,8 @@ def harvest(self, **kwargs):  # pragma: no cover
 
     def _request(self, kwargs):
         if self.http_method == 'GET':
-            return requests.get(self.endpoint, params=kwargs, **self.request_args)
-        return requests.post(self.endpoint, data=kwargs, **self.request_args)
+            return self.session.get(self.endpoint, params=kwargs, **self.request_args)
+        return self.session.post(self.endpoint, data=kwargs, **self.request_args)
 
     def ListRecords(self, ignore_deleted=False, **kwargs):
         """Issue a ListRecords request.
diff --git a/sickle/tests/test_harvesting.py b/sickle/tests/test_harvesting.py
index b0c2886..80d09ae 100644
--- a/sickle/tests/test_harvesting.py
+++ b/sickle/tests/test_harvesting.py
@@ -10,6 +10,7 @@
 
 from lxml import etree
 from nose.tools import raises
+from requests import Session
 import mock
 
 from sickle import Sickle
@@ -238,7 +239,7 @@ class TestCaseWrongEncoding(unittest.TestCase):
 
     def __init__(self, methodName='runTest'):
         super(TestCaseWrongEncoding, self).__init__(methodName)
-        self.patch = mock.patch('sickle.app.requests.get', mock_get)
+        self.patch = mock.patch.object(Session, 'get', mock_get)
 
     def setUp(self):
         self.patch.start()
diff --git a/sickle/tests/test_sickle.py b/sickle/tests/test_sickle.py
index 62b75f5..5802352 100644
--- a/sickle/tests/test_sickle.py
+++ b/sickle/tests/test_sickle.py
@@ -11,6 +11,7 @@
 from mock import patch, Mock
 from nose.tools import raises
 from requests import HTTPError
+from requests import Session
 
 from sickle import Sickle
 
@@ -33,7 +34,7 @@ def test_invalid_iterator(self):
     def test_pass_request_args(self):
         mock_response = Mock(text=u'<xml/>', content='<xml/>', status_code=200)
         mock_get = Mock(return_value=mock_response)
-        with patch('sickle.app.requests.get', mock_get):
+        with patch.object(Session, 'get', mock_get):
             sickle = Sickle('url', timeout=10, proxies=dict(),
                             auth=('user', 'password'))
             sickle.ListRecords()
@@ -45,7 +46,7 @@ def test_pass_request_args(self):
     def test_override_encoding(self):
         mock_response = Mock(text='<xml/>', content='<xml/>', status_code=200)
         mock_get = Mock(return_value=mock_response)
-        with patch('sickle.app.requests.get', mock_get):
+        with patch.object(Session, 'get', mock_get):
             sickle = Sickle('url', encoding='encoding')
             sickle.ListSets()
             mock_get.assert_called_once_with('url',
@@ -56,7 +57,7 @@ def test_no_retry(self):
                              headers={'retry-after': '10'},
                              raise_for_status=Mock(side_effect=HTTPError))
         mock_get = Mock(return_value=mock_response)
-        with patch('sickle.app.requests.get', mock_get):
+        with patch.object(Session, 'get', mock_get):
             sickle = Sickle('url')
             try:
                 sickle.ListRecords()
@@ -71,7 +72,7 @@ def test_retry_on_503(self):
         mock_get = Mock(return_value=mock_response)
         sleep_mock = Mock()
         with patch('time.sleep', sleep_mock):
-            with patch('sickle.app.requests.get', mock_get):
+            with patch.object(Session, 'get', mock_get):
                 sickle = Sickle('url', max_retries=3, default_retry_after=0)
                 try:
                     sickle.ListRecords()
@@ -87,7 +88,7 @@ def test_retry_on_custom_code(self):
         mock_response = Mock(status_code=500,
                              raise_for_status=Mock(side_effect=HTTPError))
         mock_get = Mock(return_value=mock_response)
-        with patch('sickle.app.requests.get', mock_get):
+        with patch.object(Session, 'get', mock_get):
             sickle = Sickle('url', max_retries=3, default_retry_after=0, retry_status_codes=(503, 500))
             try:
                 sickle.ListRecords()