diff --git a/CHANGELOG.md b/CHANGELOG.md
index a57769c0..5d868eed 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # Changelog
 
+* Requests sessions is initialized only once instead of it being done in each request.
+
 ## 4.41.0
 * Add extra fields in `sender` and `receiver` details in `transfer` to `Transaction`
 * Remove unused error code `AdjustmentAmountMustBeGreaterThanZero`
diff --git a/braintree/configuration.py b/braintree/configuration.py
index 45bca10e..d2622945 100644
--- a/braintree/configuration.py
+++ b/braintree/configuration.py
@@ -1,3 +1,4 @@
+import requests
 import braintree
 from braintree.credentials_parser import CredentialsParser
 from braintree.environment import Environment
@@ -101,8 +102,10 @@ def __init__(self, environment=None, merchant_id=None, public_key=None, private_
         self.access_token = parser.access_token
         self.timeout = kwargs.get("timeout", 60)
         self.wrap_http_exceptions = kwargs.get("wrap_http_exceptions", False)
-
         http_strategy = kwargs.get("http_strategy", None)
+        self.requests_session = requests.Session()
+        # Work around known proxy bug (see https://github.com/psf/requests/issues/5677)
+        self.requests_session.proxies.update(requests.utils.getproxies())
 
         if http_strategy:
             self._http_strategy = http_strategy(self, self.environment)
@@ -119,7 +122,7 @@ def graphql_base_url(self):
         return self.environment.protocol + self.environment.graphql_server_and_port + "/graphql"
 
     def http(self):
-        return braintree.util.http.Http(self)
+        return braintree.util.http.Http(self, requests_session=self.requests_session)
 
     def graphql_client(self):
         return GraphQLClient(self)
diff --git a/braintree/util/http.py b/braintree/util/http.py
index 131b36dd..79dcb283 100644
--- a/braintree/util/http.py
+++ b/braintree/util/http.py
@@ -55,9 +55,10 @@ def raise_exception_from_status(status, message=None):
         else:
             raise UnexpectedError("Unexpected HTTP_RESPONSE " + str(status))
 
-    def __init__(self, config, environment=None):
+    def __init__(self, config, environment=None, requests_session=None):
         self.config = config
         self.environment = environment or self.config.environment
+        self.requests_session = requests_session or requests.Session()
 
     def post(self, path, params=None):
         return self._make_request("POST", path, Http.ContentType.Xml, params)
@@ -100,35 +101,26 @@ def _make_request(self, http_verb, path, content_type, params=None, files=None,
                     return XmlUtil.dict_from_xml(response_body)
 
     def http_do(self, http_verb, path, headers, request_body):
-        data = request_body
-        files = None
+        data, files = request_body, None
         full_path = self.__full_path(path)
 
-        if type(request_body) is tuple:
-            data = request_body[0]
-            files = request_body[1]
+        if isinstance(request_body, tuple):
+            data, files = request_body[0], request_body[1]
 
         if (self.config.environment == Environment.Development):
           verify = False
         else:
           verify = self.environment.ssl_certificate
 
-        with requests.Session() as session:
-            request = requests.Request(
-                method=http_verb,
-                url=full_path,
-                headers=headers,
-                data=data,
-                files=files)
-            prepared_request = request.prepare()
-            prepared_request.url = full_path
-            # there's a bug in requests module that requires we manually update proxy settings,
-            # see https://github.com/psf/requests/issues/5677
-            session.proxies.update(requests.utils.getproxies())
-
-            response = session.send(prepared_request,
-                verify=verify,
-                timeout=self.config.timeout)
+        response = self.requests_session.request(
+            method=http_verb,
+            url=full_path,
+            headers=headers,
+            data=data,
+            files=files,
+            verify=verify,
+            timeout=self.config.timeout,
+        )
 
         return [response.status_code, response.text]
 
@@ -174,7 +166,8 @@ def __headers(self, content_type, header_overrides=None):
         if content_type == Http.ContentType.Xml:
             headers["Content-type"] = Http.ContentType.Xml
 
-        headers.update(header_overrides or {})
+        if header_overrides is not None:
+            headers.update(header_overrides)
 
         return headers
 
diff --git a/tests/unit/test_http.py b/tests/unit/test_http.py
index 600086aa..a31d4082 100644
--- a/tests/unit/test_http.py
+++ b/tests/unit/test_http.py
@@ -140,33 +140,16 @@ def test_http_do_strategy(http_verb, path, headers, request_body):
             http.handle_exception(requests.exceptions.ConnectTimeout())
 
     def test_request_urls_retain_dots(self):
-        with patch('requests.Session.send') as send:
+        config = Configuration(
+            Environment.Development,
+            "integration_merchant_id",
+            public_key="integration_public_key",
+            private_key="integration_private_key",
+            wrap_http_exceptions=True
+        )
+        with patch.object(config.requests_session, 'request') as send:
             send.return_value.status_code = 200
-            config = Configuration(
-                Environment.Development,
-                "integration_merchant_id",
-                public_key="integration_public_key",
-                private_key="integration_private_key",
-                wrap_http_exceptions=True
-            )
             http = config.http()
             http.get("/../../customers/")
-
-            prepared_request = send.call_args[0][0]
-            request_url = prepared_request.url
+            request_url = send.call_args[1]['url']
             self.assertTrue(request_url.endswith("/../../customers/"))
-
-    def test_sessions_close_after_request(self):
-        with patch('requests.Session.send') as send, patch('requests.Session.close') as close:
-            send.return_value.status_code = 200
-            config = Configuration(
-                Environment.Development,
-                "integration_merchant_id",
-                public_key="integration_public_key",
-                private_key="integration_private_key",
-                wrap_http_exceptions=True
-            )
-            http = config.http()
-            http.get("/../../customers/")
-
-            self.assertTrue(close.called)