diff --git a/litestar/connection/request.py b/litestar/connection/request.py
index 23c60f0b3c..154af41a29 100644
--- a/litestar/connection/request.py
+++ b/litestar/connection/request.py
@@ -1,7 +1,7 @@
 from __future__ import annotations
 
 import warnings
-from typing import TYPE_CHECKING, Any, AsyncGenerator, Generic
+from typing import TYPE_CHECKING, Any, AsyncGenerator, Generic, cast
 
 from litestar._multipart import parse_content_header, parse_multipart_form
 from litestar._parsers import parse_url_encoded_form_data
@@ -222,17 +222,7 @@ async def form(self) -> FormMultiDict:
 
                 self._connection_state.form = form_data
 
-            # form_data is a dict[str, list[str] | str | UploadFile]. Convert it to a
-            # list[tuple[str, str | UploadFile]] before passing it to FormMultiDict so
-            # multi-keys can be accessed properly
-            items = []
-            for k, v in form_data.items():
-                if isinstance(v, list):
-                    for sv in v:
-                        items.append((k, sv))
-                else:
-                    items.append((k, v))
-            self._form = FormMultiDict(items)
+            self._form = FormMultiDict.from_form_data(cast("dict[str, Any]", form_data))
 
         return self._form
 
diff --git a/litestar/datastructures/multi_dicts.py b/litestar/datastructures/multi_dicts.py
index 7702e1a8d5..733be6be0b 100644
--- a/litestar/datastructures/multi_dicts.py
+++ b/litestar/datastructures/multi_dicts.py
@@ -95,6 +95,27 @@ def copy(self) -> Self:  # type: ignore[override]
 class FormMultiDict(ImmutableMultiDict[Any]):
     """MultiDict for form data."""
 
+    @classmethod
+    def from_form_data(cls, form_data: dict[str, list[str] | str | UploadFile]) -> FormMultiDict:
+        """Create a FormMultiDict from form data.
+
+        Args:
+            form_data: Form data to create the FormMultiDict from.
+
+        Returns:
+            A FormMultiDict instance
+        """
+        # Convert form_data to a list[tuple[str, str | UploadFile]] before passing it
+        # to FormMultiDict so multi-keys can be accessed properly
+        items = []
+        for k, v in form_data.items():
+            if not isinstance(v, list):
+                items.append((k, v))
+            else:
+                for sv in v:
+                    items.append((k, sv))
+        return cls(items)
+
     async def close(self) -> None:
         """Close all files in the multi-dict.
 
diff --git a/litestar/datastructures/upload_file.py b/litestar/datastructures/upload_file.py
index 93d76476a2..78f27c92bc 100644
--- a/litestar/datastructures/upload_file.py
+++ b/litestar/datastructures/upload_file.py
@@ -94,6 +94,8 @@ async def close(self) -> None:
         Returns:
             None.
         """
+        if self.file.closed:
+            return None
         if self.rolled_to_disk:
             return await sync_to_thread(self.file.close)
         return self.file.close()
diff --git a/litestar/routes/http.py b/litestar/routes/http.py
index a8e47f1b99..2547fdce9b 100644
--- a/litestar/routes/http.py
+++ b/litestar/routes/http.py
@@ -5,7 +5,7 @@
 
 from msgspec.msgpack import decode as _decode_msgpack_plain
 
-from litestar.datastructures.upload_file import UploadFile
+from litestar.datastructures.multi_dicts import FormMultiDict
 from litestar.enums import HttpMethod, MediaType, ScopeType
 from litestar.exceptions import ClientException, ImproperlyConfiguredException, SerializationException
 from litestar.handlers.http_handlers import HTTPRouteHandler
@@ -86,8 +86,10 @@ async def handle(self, scope: HTTPScope, receive: Receive, send: Send) -> None:
         if after_response_handler := route_handler.resolve_after_response():
             await after_response_handler(request)
 
+        if request._form is not Empty:
+            await request._form.close()
         if form_data := scope.get("_form", {}):
-            await self._cleanup_temporary_files(form_data=cast("dict[str, Any]", form_data))
+            await FormMultiDict.from_form_data(cast("dict[str, Any]", form_data)).close()
 
     def create_handler_map(self) -> None:
         """Parse the ``router_handlers`` of this route and return a mapping of
@@ -258,9 +260,3 @@ def options_handler(scope: Scope) -> Response:
             include_in_schema=False,
             sync_to_thread=False,
         )(options_handler)
-
-    @staticmethod
-    async def _cleanup_temporary_files(form_data: dict[str, Any]) -> None:
-        for v in form_data.values():
-            if isinstance(v, UploadFile) and not v.file.closed:
-                await v.close()
diff --git a/pyproject.toml b/pyproject.toml
index e0cc63efa2..f5390bf0a7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -221,6 +221,9 @@ fail_under = 50
 addopts = "--strict-markers --strict-config --dist=loadgroup -m 'not server_integration'"
 asyncio_mode = "auto"
 filterwarnings = [
+  "error",
+  # https://github.com/pytest-dev/pytest-asyncio/issues/724
+  "default:.*socket.socket:pytest.PytestUnraisableExceptionWarning",
   "ignore::trio.TrioDeprecationWarning:anyio._backends._trio*:",
   "ignore::DeprecationWarning:pkg_resources.*",
   "ignore::DeprecationWarning:google.rpc",
diff --git a/tests/e2e/test_routing/conftest.py b/tests/e2e/test_routing/conftest.py
index eaa178e1ad..1295f57647 100644
--- a/tests/e2e/test_routing/conftest.py
+++ b/tests/e2e/test_routing/conftest.py
@@ -1,4 +1,3 @@
-import subprocess
 import time
 from pathlib import Path
 from typing import Callable, List
@@ -16,16 +15,13 @@ def runner(app: str, server_command: List[str]) -> None:
         tmp_path.joinpath("app.py").write_text(app)
         monkeypatch.chdir(tmp_path)
 
-        proc = psutil.Popen(
-            server_command,
-            stderr=subprocess.PIPE,
-            stdout=subprocess.PIPE,
-        )
+        proc = psutil.Popen(server_command)
 
         def kill() -> None:
             for child in proc.children(recursive=True):
                 child.kill()
             proc.kill()
+            proc.wait()
 
         request.addfinalizer(kill)
 
diff --git a/tests/unit/test_datastructures/test_multi_dicts.py b/tests/unit/test_datastructures/test_multi_dicts.py
index 78fec65f69..7ec7f386ca 100644
--- a/tests/unit/test_datastructures/test_multi_dicts.py
+++ b/tests/unit/test_datastructures/test_multi_dicts.py
@@ -1,7 +1,8 @@
 from __future__ import annotations
 
+from unittest.mock import patch
+
 import pytest
-from pytest_mock import MockerFixture
 
 from litestar.datastructures import UploadFile
 from litestar.datastructures.multi_dicts import FormMultiDict, ImmutableMultiDict, MultiDict
@@ -34,20 +35,19 @@ def test_immutable_multi_dict_as_mutable() -> None:
     assert multi.mutable_copy().dict() == MultiDict(data).dict()
 
 
-async def test_form_multi_dict_close(mocker: MockerFixture) -> None:
-    close = mocker.patch("litestar.datastructures.multi_dicts.UploadFile.close")
-
+async def test_form_multi_dict_close() -> None:
     multi = FormMultiDict(
         [
             ("foo", UploadFile(filename="foo", content_type="text/plain")),
             ("bar", UploadFile(filename="foo", content_type="text/plain")),
         ]
     )
-
+    with patch("litestar.datastructures.multi_dicts.UploadFile.close") as mock_close:
+        await multi.close()
+        assert mock_close.call_count == 2
+    # calls the real UploadFile.close method to clean up
     await multi.close()
 
-    assert close.call_count == 2
-
 
 @pytest.mark.parametrize("type_", [MultiDict, ImmutableMultiDict])
 def test_copy(type_: type[MultiDict | ImmutableMultiDict]) -> None: