diff --git a/src/Altinn.Broker.API/Controllers/LegacyFileController.cs b/src/Altinn.Broker.API/Controllers/LegacyFileController.cs
index d1d4ba8a..37f37c6e 100644
--- a/src/Altinn.Broker.API/Controllers/LegacyFileController.cs
+++ b/src/Altinn.Broker.API/Controllers/LegacyFileController.cs
@@ -71,12 +71,16 @@ CancellationToken cancellationToken
 
         LogContextHelpers.EnrichLogsWithToken(legacyToken);
         logger.LogInformation("Legacy - Uploading file for file transfer {fileId}", fileTransferId.ToString());
-        Request.EnableBuffering();
+        if (Request.ContentLength is null)
+        {
+            return Problem("Content-length header is required");
+        }
         var commandResult = await handler.Process(new UploadFileRequest()
         {
             FileTransferId = fileTransferId,
             Token = legacyToken,
             UploadStream = Request.Body,
+            ContentLength = Request.ContentLength.Value,
             IsLegacy = true
         }, HttpContext.User, cancellationToken);
         return commandResult.Match(
diff --git a/tests/Altinn.Broker.Tests/LegacyFileControllerTests.cs b/tests/Altinn.Broker.Tests/LegacyFileControllerTests.cs
index 003aca38..2349a550 100644
--- a/tests/Altinn.Broker.Tests/LegacyFileControllerTests.cs
+++ b/tests/Altinn.Broker.Tests/LegacyFileControllerTests.cs
@@ -64,6 +64,7 @@ public async Task InitializeAndUpload_Success()
         }
         var fileAfterUpload = await _legacyClient.GetFromJsonAsync<LegacyFileOverviewExt>($"broker/api/v1/legacy/file/{fileId}?onBehalfOfConsumer={onBehalfOfConsumer}", _responseSerializerOptions);
         Assert.NotNull(fileAfterUpload);
+        Assert.True(fileAfterUpload.FileSize == uploadedFileBytes.Length);
         Assert.Equal(LegacyFileStatusExt.Published, fileAfterUpload.FileStatus); // When running integration test this happens instantly as of now.
     }