diff --git a/src/GitHub_Updater/Rest_Update.php b/src/GitHub_Updater/Rest_Update.php
index <HASH>..<HASH> 100644
--- a/src/GitHub_Updater/Rest_Update.php
+++ b/src/GitHub_Updater/Rest_Update.php
@@ -230,6 +230,9 @@ class Rest_Update {
 			 */
 			do_action( 'github_updater_pre_rest_process_request' );
 
+			// Add authentication header to download package.
+			add_filter( 'http_request_args', [ Singleton::get_instance( 'API', $this ), 'download_package' ], 10, 2 );
+
 			$this->get_webhook_source();
 			$tag            = $committish ? $committish : $tag;
 			$current_branch = $this->get_local_branch( $plugin, $theme );
add filter for download package to REST_Update