diff --git a/phpBB/includes/functions_admin.php b/phpBB/includes/functions_admin.php
index 4eaedc4041..11a672a2ed 100644
--- a/phpBB/includes/functions_admin.php
+++ b/phpBB/includes/functions_admin.php
@@ -894,11 +894,11 @@ function delete_topics($where_type, $where_ids, $auto_sync = true, $post_count_s
 	/* @var $phpbb_notifications \phpbb\notification\manager */
 	$phpbb_notifications = $phpbb_container->get('notification_manager');
 
-	$phpbb_notifications->delete_notifications(array(
+	$phpbb_notifications->delete_notifications_by_types([
 		'notification.type.topic',
 		'notification.type.approve_topic',
 		'notification.type.topic_in_queue',
-	), $topic_ids);
+	], $topic_ids);
 
 	return $return;
 }
@@ -1185,7 +1185,7 @@ function delete_posts($where_type, $where_ids, $auto_sync = true, $posted_sync =
 	/* @var $phpbb_notifications \phpbb\notification\manager */
 	$phpbb_notifications = $phpbb_container->get('notification_manager');
 
-	$phpbb_notifications->delete_notifications($delete_notifications_types, $post_ids);
+	$phpbb_notifications->delete_notifications_by_types($delete_notifications_types, $post_ids);
 
 	return count($post_ids);
 }
diff --git a/phpBB/phpbb/notification/manager.php b/phpBB/phpbb/notification/manager.php
index e25c0f2952..9c4fe8203a 100644
--- a/phpBB/phpbb/notification/manager.php
+++ b/phpBB/phpbb/notification/manager.php
@@ -474,25 +474,17 @@ class manager
 	}
 
 	/**
-	* Delete a notification
-	*
-	* @param string|array $notification_type_name Type identifier or array of item types (only acceptable if the $item_id is identical for the specified types)
-	* @param int|array $item_id Identifier within the type (or array of ids)
-	* @param mixed $parent_id Parent identifier within the type (or array of ids), used in combination with item_id if specified (Default: false; not checked)
-	* @param mixed $user_id User id (Default: false; not checked)
+	 * Delete notifications of specified type
+	 *
+	 * @param string $notification_type_name Type identifier
+	 * @param int|array $item_id Identifier within the type (or array of ids)
+	 * @param mixed $parent_id Parent identifier within the type (or array of ids), used in combination with item_id if specified (Default: false; not checked)
+	 * @param mixed $user_id User id (Default: false; not checked)
+	 *
+	 * @return void
 	*/
-	public function delete_notifications($notification_type_name, $item_id, $parent_id = false, $user_id = false)
+	public function delete_notifications(string $notification_type_name, $item_id, $parent_id = false, $user_id = false): void
 	{
-		if (is_array($notification_type_name))
-		{
-			foreach ($notification_type_name as $type)
-			{
-				$this->delete_notifications($type, $item_id, $parent_id, $user_id);
-			}
-
-			return;
-		}
-
 		$notification_type_id = $this->get_notification_type_id($notification_type_name);
 
 		/** @var method\method_interface $method */
@@ -502,6 +494,24 @@ class manager
 		}
 	}
 
+	/**
+	 * Delete notifications specified by multiple types
+	 *
+	 * @param array $notification_type_names Array of item types (only acceptable if the $item_id is identical for the specified types)
+	 * @param int|array $item_id Identifier within the type (or array of ids)
+	 * @param mixed $parent_id Parent identifier within the type (or array of ids), used in combination with item_id if specified (Default: false; not checked)
+	 * @param mixed $user_id User id (Default: false; not checked)
+	 *
+	 * @return void
+	 */
+	public function delete_notifications_by_types(array $notification_type_names, $item_id, $parent_id = false, $user_id = false): void
+	{
+		foreach ($notification_type_names as $type)
+		{
+			$this->delete_notifications($type, $item_id, $parent_id, $user_id);
+		}
+	}
+
 	/**
 	* Get all of the subscription types
 	*
diff --git a/tests/mock/notification_manager.php b/tests/mock/notification_manager.php
index 952c0db489..0b70d264eb 100644
--- a/tests/mock/notification_manager.php
+++ b/tests/mock/notification_manager.php
@@ -61,6 +61,10 @@ class phpbb_mock_notification_manager
 	{
 	}
 
+	public function delete_notifications_by_types()
+	{
+	}
+
 	public function get_subscription_types()
 	{
 		return array();