diff --git a/phpBB/includes/nestedset/base.php b/phpBB/includes/nestedset/base.php
index 56422f52a5..630512d713 100644
--- a/phpBB/includes/nestedset/base.php
+++ b/phpBB/includes/nestedset/base.php
@@ -30,11 +30,11 @@ abstract class phpbb_nestedset_base implements phpbb_nestedset_interface
 	* Column names in the table
 	* @var String
 	*/
-	protected $columns_item_id = 'item_id';
-	protected $columns_left_id = 'left_id';
-	protected $columns_right_id = 'right_id';
-	protected $columns_parent_id = 'parent_id';
-	protected $columns_item_parents = 'item_parents';
+	protected $column_item_id = 'item_id';
+	protected $column_left_id = 'left_id';
+	protected $column_right_id = 'right_id';
+	protected $column_parent_id = 'parent_id';
+	protected $column_item_parents = 'item_parents';
 
 	/**
 	* Additional SQL restrictions
diff --git a/phpBB/includes/nestedset/forum.php b/phpBB/includes/nestedset/forum.php
index e00754eb68..18936c1c55 100644
--- a/phpBB/includes/nestedset/forum.php
+++ b/phpBB/includes/nestedset/forum.php
@@ -33,8 +33,8 @@ class phpbb_nestedset_forum extends phpbb_nestedset_base
 	* Column names in the table
 	* @var String
 	*/
-	protected $columns_item_id = 'forum_id';
-	protected $columns_item_parents = 'forum_parents';
+	protected $column_item_id = 'forum_id';
+	protected $column_item_parents = 'forum_parents';
 
 	/**
 	* Additional SQL restrictions