diff --git a/includes/libs/rdbms/querybuilder/SelectQueryBuilder.php b/includes/libs/rdbms/querybuilder/SelectQueryBuilder.php
index 405e86d740d..f74a455432e 100644
--- a/includes/libs/rdbms/querybuilder/SelectQueryBuilder.php
+++ b/includes/libs/rdbms/querybuilder/SelectQueryBuilder.php
@@ -2,6 +2,12 @@
 
 namespace Wikimedia\Rdbms;
 
+/**
+ * @stable to extend. Note that none of the methods in this class are stable to override.
+ * The goal of extending this class is creating specialized query builders,
+ * like {@link \MediaWiki\Page\PageSelectQueryBuilder}
+ * @package Wikimedia\Rdbms
+ */
 class SelectQueryBuilder extends JoinGroupBase {
 
 	/** @var string sort the results in ascending order */