diff --git a/UPGRADE.md b/UPGRADE.md
index beed13b5732..63dd8b279dd 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -9,6 +9,10 @@ The usage of the `andX()` and `orX()` methods of the `ExpressionBuilder` class h
 The usage of the `add()` and `addMultiple()` methods of the `CompositeExpression` class has been deprecated. Use `with()` instead, which returns a new instance.
 In the future, the `add*()` methods will be removed and the class will be effectively immutable.
 
+## Deprecated calling `QueryBuilder` methods with an array argument
+
+Calling the `select()`, `addSelect()`, `groupBy()` and `addGroupBy()` methods with an array argument is deprecated.
+
 # Upgrade to 2.10
 
 ## Deprecated `Doctrine\DBAL\Event\ConnectionEventArgs` methods
diff --git a/lib/Doctrine/DBAL/Query/QueryBuilder.php b/lib/Doctrine/DBAL/Query/QueryBuilder.php
index 58d7062f0a7..1f050c681d8 100644
--- a/lib/Doctrine/DBAL/Query/QueryBuilder.php
+++ b/lib/Doctrine/DBAL/Query/QueryBuilder.php
@@ -451,6 +451,8 @@ public function add($sqlPartName, $sqlPart, $append = false)
      * Specifies an item that is to be returned in the query result.
      * Replaces any previously specified selections, if any.
      *
+     * USING AN ARRAY ARGUMENT IS DEPRECATED. This feature will be removed in the next major version.
+     *
      * <code>
      *     $qb = $conn->createQueryBuilder()
      *         ->select('u.id', 'p.id')
@@ -497,6 +499,8 @@ public function distinct() : self
     /**
      * Adds an item that is to be returned in the query result.
      *
+     * USING AN ARRAY ARGUMENT IS DEPRECATED. This feature will be removed in the next major version.
+     *
      * <code>
      *     $qb = $conn->createQueryBuilder()
      *         ->select('u.id')
@@ -869,6 +873,8 @@ public function orWhere($where)
      * Specifies a grouping over the results of the query.
      * Replaces any previously specified groupings, if any.
      *
+     * USING AN ARRAY ARGUMENT IS DEPRECATED. This feature will be removed in the next major version.
+     *
      * <code>
      *     $qb = $conn->createQueryBuilder()
      *         ->select('u.name')
@@ -894,6 +900,8 @@ public function groupBy($groupBy)
     /**
      * Adds a grouping expression to the query.
      *
+     * USING AN ARRAY ARGUMENT IS DEPRECATED. This feature will be removed in the next major version.
+     *
      * <code>
      *     $qb = $conn->createQueryBuilder()
      *         ->select('u.name')