diff --git a/cmd/testworkflow-toolkit/artifacts/cloud_uploader.go b/cmd/testworkflow-toolkit/artifacts/cloud_uploader.go
index 62aa587da9..11d76de5a1 100644
--- a/cmd/testworkflow-toolkit/artifacts/cloud_uploader.go
+++ b/cmd/testworkflow-toolkit/artifacts/cloud_uploader.go
@@ -86,6 +86,10 @@ func (d *cloudUploader) getContentType(path string, size int64) string {
 func (d *cloudUploader) putObject(url string, path string, file io.Reader, size int64) error {
 	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Minute)
 	defer cancel()
+	if size == 0 {
+		// http.Request won't send Content-Length: 0, if the body is non-nil
+		file = nil
+	}
 	req, err := http.NewRequestWithContext(ctx, http.MethodPut, url, file)
 	if err != nil {
 		return err
diff --git a/pkg/cloud/data/testworkflow/output.go b/pkg/cloud/data/testworkflow/output.go
index a08be8a0ee..1ae07c6c96 100644
--- a/pkg/cloud/data/testworkflow/output.go
+++ b/pkg/cloud/data/testworkflow/output.go
@@ -65,7 +65,14 @@ func (r *CloudOutputRepository) SaveLog(ctx context.Context, id, workflowName st
 	if err != nil {
 		return err
 	}
-	defer buffer.Cleanup()
+	bufferLen := buffer.Len()
+	if bufferLen == 0 {
+		// http.Request won't send Content-Length: 0, if the body is non-nil
+		buffer.Cleanup()
+		buffer = nil
+	} else {
+		defer buffer.Cleanup()
+	}
 	url, err := r.PresignSaveLog(ctx, id, workflowName)
 	if err != nil {
 		return err
@@ -75,7 +82,7 @@ func (r *CloudOutputRepository) SaveLog(ctx context.Context, id, workflowName st
 		return err
 	}
 	req.Header.Add("Content-Type", "application/octet-stream")
-	req.ContentLength = int64(buffer.Len())
+	req.ContentLength = int64(bufferLen)
 	res, err := r.httpClient.Do(req)
 	if err != nil {
 		return errors.Wrap(err, "failed to save file in cloud storage")