diff --git a/wp-includes/rest-api/endpoints/class-wp-rest-controller.php b/wp-includes/rest-api/endpoints/class-wp-rest-controller.php
index 0d1e85cbf1..44880aaec2 100644
--- a/wp-includes/rest-api/endpoints/class-wp-rest-controller.php
+++ b/wp-includes/rest-api/endpoints/class-wp-rest-controller.php
@@ -645,6 +645,7 @@ abstract class WP_REST_Controller {
 			'pattern',
 			'minItems',
 			'maxItems',
+			'uniqueItems',
 		);
 
 		foreach ( $schema_properties as $field_id => $params ) {
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 08cdad1546..331be90ff6 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.5.1-alpha-48806';
+$wp_version = '5.5.1-alpha-48807';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.