diff --git a/starlette/datastructures.py b/starlette/datastructures.py
index 8dad7b0b50..558730c45b 100644
--- a/starlette/datastructures.py
+++ b/starlette/datastructures.py
@@ -449,11 +449,11 @@ async def read(self, size: int = -1) -> typing.Union[bytes, str]:
             return self.file.read(size)
         return await run_in_threadpool(self.file.read, size)
 
-    async def seek(self, offset: int) -> None:
+    async def seek(self, offset: int, whence: int) -> None:
         if self._in_memory:
-            self.file.seek(offset)
+            self.file.seek(offset, whence)
         else:
-            await run_in_threadpool(self.file.seek, offset)
+            await run_in_threadpool(self.file.seek, offset, whence)
 
     async def close(self) -> None:
         if self._in_memory:
diff --git a/tests/test_datastructures.py b/tests/test_datastructures.py
index b0e6baf985..bd356c236f 100644
--- a/tests/test_datastructures.py
+++ b/tests/test_datastructures.py
@@ -222,7 +222,7 @@ async def test_upload_file():
     big_file = BigUploadFile("big-file")
     await big_file.write(b"big-data" * 512)
     await big_file.write(b"big-data")
-    await big_file.seek(0)
+    await big_file.seek(0, 0)
     assert await big_file.read(1024) == b"big-data" * 128
     await big_file.close()