diff --git a/core/Object.php b/core/Object.php
index fc7988f78..2ca0bdefa 100755
--- a/core/Object.php
+++ b/core/Object.php
@@ -403,7 +403,7 @@ class Object {
 	 * 
 	 * @return DataObjectDecorator The instance of the extension
 	 */
-	public function getExtension($name) {
+	public function extInstance($name) {
 		return $this->extension_instances[$name];
 	}
 	
diff --git a/core/model/Hierarchy.php b/core/model/Hierarchy.php
index 16c5d372d..e5df0c508 100644
--- a/core/model/Hierarchy.php
+++ b/core/model/Hierarchy.php
@@ -335,7 +335,7 @@ class Hierarchy extends DataObjectDecorator {
 					continue;
 				}
 				$idList[] = $child->ID;
-				$child->getExtension('Hierarchy')->loadDescendantIDListInto($idList);
+				$child->extInstance('Hierarchy')->loadDescendantIDListInto($idList);
 			}
 		}
 	}
diff --git a/core/model/Versioned.php b/core/model/Versioned.php
index 891f7e5a0..ace049780 100755
--- a/core/model/Versioned.php
+++ b/core/model/Versioned.php
@@ -159,7 +159,7 @@ class Versioned extends DataObjectDecorator {
 				if($this->owner->parentClass() == "DataObject") {
 					$rootTable = true;
 				}
-				if ($suffix && ($ext = $this->owner->getExtension($allSuffixes[$suffix]))) {
+				if ($suffix && ($ext = $this->owner->extInstance($allSuffixes[$suffix]))) {
 					if (!$ext->isVersionedTable($table)) continue;
 					$fields = $ext->fieldsInExtraTables($suffix);
 					$indexes = $fields['indexes'];
@@ -345,7 +345,7 @@ class Versioned extends DataObjectDecorator {
 	function extendWithSuffix($table) {
 		foreach (Versioned::$versionableExtensions as $versionableExtension => $suffixes) {
 			if ($this->owner->hasExtension($versionableExtension)) {
-				$table = $this->owner->getExtension($versionableExtension)->extendWithSuffix($table);
+				$table = $this->owner->extInstance($versionableExtension)->extendWithSuffix($table);
 			}
 		}
 		return $table;