diff --git a/src/wp-admin/includes/media.php b/src/wp-admin/includes/media.php
index 8181ba5ad0..176ab986ac 100644
--- a/src/wp-admin/includes/media.php
+++ b/src/wp-admin/includes/media.php
@@ -141,7 +141,8 @@ function get_image_send_to_editor( $id, $caption, $title, $align, $url = '', $re
 	 * @param string $title   The image title.
 	 * @param string $align   The image alignment.
 	 * @param string $url     The image source URL.
-	 * @param string $size    The image size.
+	 * @param string|array $size Size of image. Image size or array of width and height values
+ *                               (in that order).
 	 * @param string $alt     The image alternative, or alt, text.
 	 */
 	$html = apply_filters( 'image_send_to_editor', $html, $id, $caption, $title, $align, $url, $size, $alt );