diff --git a/src/scratch/ScratchRuntime.as b/src/scratch/ScratchRuntime.as
index a339b97..ac2552f 100644
--- a/src/scratch/ScratchRuntime.as
+++ b/src/scratch/ScratchRuntime.as
@@ -664,7 +664,7 @@ public class ScratchRuntime {
 	public function renameSprite(newName:String):void {
 		var obj:ScratchObj = app.viewedObj();
 		obj.objName = '';
-		newName = app.stagePane.unusedSpriteName(newName);
+		newName = app.stagePane.unusedSpriteName(newName || 'Sprite1');
 		var oldName:String = obj.objName;
 		obj.objName = newName;
 		for each (var lw:ListWatcher in app.viewedObj().lists) {