diff --git a/core/model/Hierarchy.php b/core/model/Hierarchy.php
index 3a858b7e9..8ddc13ea0 100755
--- a/core/model/Hierarchy.php
+++ b/core/model/Hierarchy.php
@@ -24,6 +24,15 @@ class Hierarchy extends DataObjectDecorator {
 	
 	function augmentWrite(&$manipulation) {
 	}
+	
+	function extraStatics($class = null) {
+		return array(
+			'has_one' => array(
+				// TODO this method is called *both* statically and on an instance
+				"Parent" => ($class) ? $class : $this->owner->class
+			)
+		);
+	}
 
 	/**
 	 * Returns the children of this DataObject as an XHTML UL. This will be called recursively on each child,
diff --git a/core/model/SiteTree.php b/core/model/SiteTree.php
index bed72a77b..dbec7907b 100755
--- a/core/model/SiteTree.php
+++ b/core/model/SiteTree.php
@@ -123,10 +123,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 		"CanEditType" => "Inherit"
 	);
 
-	static $has_one = array(
-		"Parent" => "SiteTree"
-	);
-
 	static $versioning = array(
 		"Stage",  "Live"
 	);