diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1bc2f92..3ea4360 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## Unreleased
+### Added
+  * `RequestsHTTPClient`: optional `requester` parameter
 
 
 ## [0.4.3] - 2026-03-14
diff --git a/Makefile b/Makefile
index dfa4548..9e112bf 100644
--- a/Makefile
+++ b/Makefile
@@ -33,6 +33,8 @@ lint:
 	flake8 $(PACKAGE) tests
 	pylint --rcfile=pyproject.toml $(PACKAGE) tests
 	mypy $(PACKAGE) tests
+
+audit:
 	pip-audit -l
 
 .PHONY: testall
diff --git a/httprest/http/requests_client.py b/httprest/http/requests_client.py
index 6824183..db663eb 100644
--- a/httprest/http/requests_client.py
+++ b/httprest/http/requests_client.py
@@ -1,5 +1,6 @@
 """HTTP client which uses `requests` under the hood."""
 
+from types import ModuleType
 from typing import Optional, Union
 
 import requests
@@ -12,11 +13,25 @@
 
 
 class RequestsHTTPClient(HTTPClient):
-    """`requests` HTTP client."""
+    """`requests` HTTP client.
 
-    def __init__(self, timeout: Optional[Timeout] = None) -> None:
+    By default a reusable ``requests.Session`` is used (connection reuse).
+    Pass ``requester`` to override this:
+
+    * a custom ``requests.Session`` (e.g. with retries/adapters configured), or
+    * the ``requests`` module itself, to make independent module-level calls
+      with no connection reuse.
+    """
+
+    def __init__(
+        self,
+        timeout: Optional[Timeout] = None,
+        requester: Optional[Union[requests.Session, ModuleType]] = None,
+    ) -> None:
         super().__init__(timeout)
-        self._session = requests.Session()
+        self._requester = (
+            requester if requester is not None else requests.Session()
+        )
 
     def _request(
         self,
@@ -37,7 +52,7 @@ def _request(
             )
         try:
             response: requests.Response = getattr(
-                self._session, method.lower()
+                self._requester, method.lower()
             )(
                 url,
                 data=data,
diff --git a/tests/unit/http/test_requests_client.py b/tests/unit/http/test_requests_client.py
index 16ee597..e1ff293 100644
--- a/tests/unit/http/test_requests_client.py
+++ b/tests/unit/http/test_requests_client.py
@@ -81,3 +81,34 @@ def test_query_params():
         "get", "https://example.com", params={"p": "hello/world"}
     )
     assert response.status_code == 200
+
+
+@responses.activate
+def test_requester_module():
+    """Test using the `requests` module directly (no session)."""
+    responses.add(responses.GET, "https://example.com", json={"k": "v"})
+    client = RequestsHTTPClient(requester=requests)
+    response = client.request("get", "https://example.com")
+    assert response.status_code == 200
+    assert response.json == {"k": "v"}
+
+
+@responses.activate
+def test_injected_session_is_used():
+    """An injected session must be the one actually performing the request.
+
+    The session carries a custom header that a default, internally-created
+    session would not have. The request is only matched (and succeeds) if it
+    goes through this exact session, so matching proves it is used -- no need
+    to inspect the client's internals.
+    """
+    responses.get(
+        "https://example.com",
+        json={"k": "v"},
+        match=[matchers.header_matcher({"X-Custom": "v"})],
+    )
+    session = requests.Session()
+    session.headers["X-Custom"] = "v"
+    client = RequestsHTTPClient(requester=session)
+    response = client.request("get", "https://example.com")
+    assert response.status_code == 200