diff --git a/lib/class-wp-rest-block-directory-controller.php b/lib/class-wp-rest-block-directory-controller.php
index 0ca7ac1670552..9e911d28c9bd0 100644
--- a/lib/class-wp-rest-block-directory-controller.php
+++ b/lib/class-wp-rest-block-directory-controller.php
@@ -10,6 +10,8 @@
 /**
  * Controller which provides REST endpoint for the blocks.
  *
+ * This class can be removed when plugin support requires WordPress 5.5.0+.
+ *
  * @since 5.5.0
  *
  * @see   WP_REST_Controller
diff --git a/lib/class-wp-rest-plugins-controller.php b/lib/class-wp-rest-plugins-controller.php
index 98c7cfa27174c..49a55192dad20 100644
--- a/lib/class-wp-rest-plugins-controller.php
+++ b/lib/class-wp-rest-plugins-controller.php
@@ -10,6 +10,8 @@
 /**
  * Core class to access plugins via the REST API.
  *
+ * This class can be removed when plugin support requires WordPress 5.5.0+.
+ *
  * @since 5.5.0
  *
  * @see   WP_REST_Controller