diff --git a/lib/experimental/media/load.php b/lib/experimental/media/load.php
index bcb02accf62a6b..18bfd22d4de00f 100644
--- a/lib/experimental/media/load.php
+++ b/lib/experimental/media/load.php
@@ -247,6 +247,8 @@ function gutenberg_set_up_cross_origin_isolation() {
  * Uses an output buffer to add crossorigin="anonymous" where needed.
  *
  * @link https://web.dev/coop-coep/
+ *
+ * @global bool $is_safari
  */
 function gutenberg_start_cross_origin_isolation_output_buffer(): void {
 	global $is_safari;