diff --git a/code/CMSMain.php b/code/CMSMain.php
index 1d1eb557..f584db12 100755
--- a/code/CMSMain.php
+++ b/code/CMSMain.php
@@ -564,7 +564,7 @@ JS;
 		
 		// before deleting the records, get the descendants of this tree
 		if($record) {
-			$descendantIDs = $record->getDescendantIDList('SiteTree');
+			$descendantIDs = $record->getDescendantIDList();
 
 			// then delete them from the live site too
 			$descendantsRemoved = 0;
diff --git a/code/ThumbnailStripField.php b/code/ThumbnailStripField.php
index ed4eb758..441add29 100755
--- a/code/ThumbnailStripField.php
+++ b/code/ThumbnailStripField.php
@@ -44,7 +44,7 @@ class ThumbnailStripField extends FormField {
 		$folder = DataObject::get_by_id('Folder', (int) $_GET['folderID']);
 		
 		if($folder) {
-			$folderList = $folder->getDescendantIDList('Folder');
+			$folderList = $folder->getDescendantIDList();
 			array_unshift($folderList, $folder->ID);
 
 			$whereSQL = '"ParentID" IN (' . implode(', ', $folderList) . ')';