diff --git a/src/writerai/resources/files.py b/src/writerai/resources/files.py
index 83f5550..00f7824 100644
--- a/src/writerai/resources/files.py
+++ b/src/writerai/resources/files.py
@@ -6,12 +6,9 @@
 
 import httpx
 
-from ..types import file_list_params, file_upload_params
+from ..types import file_list_params
 from .._types import NOT_GIVEN, Body, Query, Headers, NotGiven, FileTypes
-from .._utils import (
-    maybe_transform,
-    async_maybe_transform,
-)
+from .._utils import maybe_transform
 from .._compat import cached_property
 from .._resource import SyncAPIResource, AsyncAPIResource
 from .._response import (
@@ -199,7 +196,6 @@ def upload(
         *,
         content: FileTypes,
         content_disposition: str,
-        content_length: int,
         content_type: str,
         # Use the following arguments if you need to pass additional parameters to the API that aren't available via kwargs.
         # The extra values given here take precedence over values defined on the client or passed to this method.
@@ -222,7 +218,6 @@ def upload(
         """
         extra_headers = {
             "Content-Disposition": content_disposition,
-            "Content-Length": str(content_length),
             "Content-Type": content_type,
             **(extra_headers or {}),
         }
@@ -399,7 +394,6 @@ async def upload(
         *,
         content: FileTypes,
         content_disposition: str,
-        content_length: int,
         content_type: str,
         # Use the following arguments if you need to pass additional parameters to the API that aren't available via kwargs.
         # The extra values given here take precedence over values defined on the client or passed to this method.
@@ -422,7 +416,6 @@ async def upload(
         """
         extra_headers = {
             "Content-Disposition": content_disposition,
-            "Content-Length": str(content_length),
             "Content-Type": content_type,
             **(extra_headers or {}),
         }
diff --git a/tests/api_resources/test_files.py b/tests/api_resources/test_files.py
index aaa93d8..5cccdf8 100644
--- a/tests/api_resources/test_files.py
+++ b/tests/api_resources/test_files.py
@@ -198,7 +198,6 @@ def test_method_upload(self, client: Writer) -> None:
         file = client.files.upload(
             content=b"raw file contents",
             content_disposition="Content-Disposition",
-            content_length=0,
             content_type="Content-Type",
         )
         assert_matches_type(File, file, path=["response"])
@@ -209,7 +208,6 @@ def test_raw_response_upload(self, client: Writer) -> None:
         response = client.files.with_raw_response.upload(
             content=b"raw file contents",
             content_disposition="Content-Disposition",
-            content_length=0,
             content_type="Content-Type",
         )
 
@@ -224,7 +222,6 @@ def test_streaming_response_upload(self, client: Writer) -> None:
         with client.files.with_streaming_response.upload(
             content=b"raw file contents",
             content_disposition="Content-Disposition",
-            content_length=0,
             content_type="Content-Type",
         ) as response:
             assert not response.is_closed
@@ -411,7 +408,6 @@ async def test_method_upload(self, async_client: AsyncWriter) -> None:
         file = await async_client.files.upload(
             content=b"raw file contents",
             content_disposition="Content-Disposition",
-            content_length=0,
             content_type="Content-Type",
         )
         assert_matches_type(File, file, path=["response"])
@@ -422,7 +418,6 @@ async def test_raw_response_upload(self, async_client: AsyncWriter) -> None:
         response = await async_client.files.with_raw_response.upload(
             content=b"raw file contents",
             content_disposition="Content-Disposition",
-            content_length=0,
             content_type="Content-Type",
         )
 
@@ -437,7 +432,6 @@ async def test_streaming_response_upload(self, async_client: AsyncWriter) -> Non
         async with async_client.files.with_streaming_response.upload(
             content=b"raw file contents",
             content_disposition="Content-Disposition",
-            content_length=0,
             content_type="Content-Type",
         ) as response:
             assert not response.is_closed