diff --git a/source/_components/downloader.markdown b/source/_components/downloader.markdown
index c3cec44022b..c616cc40688 100644
--- a/source/_components/downloader.markdown
+++ b/source/_components/downloader.markdown
@@ -40,4 +40,5 @@ This will download the file from the given URL.
 | ---------------------- | -------- | ---------------------------------------------- |
 | `url`                  |       no | The url of the file to download.               |
 | `subdir`               |      yes | Download into subdirectory of **download_dir** |
+| `filename`             |      yes | Determine the filename.                        |