diff --git a/CHANGES/5704.feature b/CHANGES/5704.feature
new file mode 100644
index 00000000000..6f9951bc993
--- /dev/null
+++ b/CHANGES/5704.feature
@@ -0,0 +1 @@
+A new argument ``client_max_size`` was added to ``BaseRequest.clone`` method to allow overriding the request body size -- :user:`anesabml`.
diff --git a/aiohttp/web_request.py b/aiohttp/web_request.py
index 6646a82f6ca..46a2aeb05b8 100644
--- a/aiohttp/web_request.py
+++ b/aiohttp/web_request.py
@@ -205,6 +205,7 @@ def clone(
         scheme: Union[str, _SENTINEL] = sentinel,
         host: Union[str, _SENTINEL] = sentinel,
         remote: Union[str, _SENTINEL] = sentinel,
+        client_max_size: Union[int, _SENTINEL] = sentinel,
     ) -> "BaseRequest":
         """Clone itself with replacement some attributes.
 
@@ -239,6 +240,8 @@ def clone(
             kwargs["host"] = host
         if remote is not sentinel:
             kwargs["remote"] = remote
+        if client_max_size is sentinel:
+            client_max_size = self._client_max_size
 
         return self.__class__(
             message,
@@ -247,7 +250,7 @@ def clone(
             self._payload_writer,
             self._task,
             self._loop,
-            client_max_size=self._client_max_size,
+            client_max_size=client_max_size,
             state=self._state.copy(),
             **kwargs,
         )
@@ -270,6 +273,10 @@ def transport(self) -> Optional[asyncio.Transport]:
     def writer(self) -> AbstractStreamWriter:
         return self._payload_writer
 
+    @property
+    def client_max_size(self) -> int:
+        return self._client_max_size
+
     @reify
     def rel_url(self) -> URL:
         return self._rel_url
@@ -852,6 +859,7 @@ def clone(
         scheme: Union[str, _SENTINEL] = sentinel,
         host: Union[str, _SENTINEL] = sentinel,
         remote: Union[str, _SENTINEL] = sentinel,
+        client_max_size: Union[int, _SENTINEL] = sentinel,
     ) -> "Request":
         ret = super().clone(
             method=method,
@@ -860,6 +868,7 @@ def clone(
             scheme=scheme,
             host=host,
             remote=remote,
+            client_max_size=client_max_size,
         )
         new_ret = cast(Request, ret)
         new_ret._match_info = self._match_info
diff --git a/docs/web_advanced.rst b/docs/web_advanced.rst
index 480becf97c7..ab44078c3ad 100644
--- a/docs/web_advanced.rst
+++ b/docs/web_advanced.rst
@@ -974,9 +974,9 @@ headers too, pushing non-trusted data values.
 That's why *aiohttp server* should setup *forwarded* headers in custom
 middleware in tight conjunction with *reverse proxy configuration*.
 
-For changing :attr:`BaseRequest.scheme` :attr:`BaseRequest.host` and
-:attr:`BaseRequest.remote` the middleware might use
-:meth:`BaseRequest.clone`.
+For changing :attr:`BaseRequest.scheme` :attr:`BaseRequest.host`
+:attr:`BaseRequest.remote` and :attr:`BaseRequest.client_max_size`
+the middleware might use :meth:`BaseRequest.clone`.
 
 .. seealso::
 
diff --git a/docs/web_reference.rst b/docs/web_reference.rst
index bc60bcabd28..417238361a8 100644
--- a/docs/web_reference.rst
+++ b/docs/web_reference.rst
@@ -149,6 +149,23 @@ and :ref:`aiohttp-web-signals` handlers.
 
       .. seealso:: :ref:`aiohttp-web-forwarded-support`
 
+   .. attribute:: client_max_size
+
+      The maximum size of the request body.
+
+      The value could be overridden by :meth:`~BaseRequest.clone`.
+
+      Read-only :class:`int` property.
+
+      .. versionchanged:: 3.8
+
+         *Forwarded* and *X-Forwarded-Proto* are not used anymore.
+
+         Call ``.clone(client_max_size=new_size)`` for setting up the value
+         explicitly.
+
+      .. seealso:: :ref:`aiohttp-web-forwarded-support`
+
    .. attribute:: path_qs
 
       The URL including PATH_INFO and the query string. e.g.,
diff --git a/tests/test_web_request.py b/tests/test_web_request.py
index b4d6514d16a..60c34319ddc 100644
--- a/tests/test_web_request.py
+++ b/tests/test_web_request.py
@@ -513,6 +513,12 @@ def test_clone_client_max_size() -> None:
     assert req2._client_max_size == 1024
 
 
+def test_clone_override_client_max_size() -> None:
+    req = make_mocked_request("GET", "/path", client_max_size=1024)
+    req2 = req.clone(client_max_size=2048)
+    assert req2.client_max_size == 2048
+
+
 def test_clone_method() -> None:
     req = make_mocked_request("GET", "/path")
     req2 = req.clone(method="POST")