diff --git a/src/scratch/ScratchRuntime.as b/src/scratch/ScratchRuntime.as
index 543132d..7f3f374 100644
--- a/src/scratch/ScratchRuntime.as
+++ b/src/scratch/ScratchRuntime.as
@@ -665,6 +665,19 @@ public class ScratchRuntime {
 	// Script utilities
 	//------------------------------
 
+	public function renameCostume(newName:String):void {
+		var obj:ScratchObj = app.viewedObj();
+		var costume:ScratchCostume = obj.currentCostume();
+		var oldName:String = costume.costumeName;
+		if (obj.isCostumeNameUsed(newName)) return;
+		costume.costumeName = newName;
+		var uses:Array = obj.isStage ? allUsesOfBackdrop(oldName) : allUsesOfCostume(oldName);
+		for each (var a:BlockArg in uses) {
+			a.setArgValue(newName);
+		}
+		app.setSaveNeeded();
+	}
+
 	public function clearRunFeedback():void {
 		if(app.editMode) {
 			for each (var stack:Block in allStacks()) {
@@ -721,6 +734,30 @@ public class ScratchRuntime {
 		return false;
 	}
 
+	public function allUsesOfBackdrop(backdropName:String):Array {
+		var result:Array = [];
+		allStacksAndOwnersDo(function (stack:Block, target:ScratchObj):void {
+			stack.allBlocksDo(function (b:Block):void {
+				for each (var a:BlockArg in b.args) {
+					if (a.menuName == 'backdrop' && a.argValue == backdropName) result.push(a);
+				}
+			});
+		});
+		return result;
+	}
+
+	public function allUsesOfCostume(costumeName:String):Array {
+		var result:Array = [];
+		for each (var stack:Block in app.viewedObj().scripts) {
+			stack.allBlocksDo(function (b:Block):void {
+				for each (var a:BlockArg in b.args) {
+					if (a.menuName == 'costume' && a.argValue == costumeName) result.push(a);
+				}
+			});
+		}
+		return result;
+	}
+
 	public function allUsesOfVariable(varName:String, owner:ScratchObj):Array {
 		var variableBlocks:Array = [Specs.SET_VAR, Specs.CHANGE_VAR, "showVariable:", "hideVariable:"];
 		var result:Array = [];
diff --git a/src/ui/parts/ImagesPart.as b/src/ui/parts/ImagesPart.as
index eb05d00..4ebdbb2 100644
--- a/src/ui/parts/ImagesPart.as
+++ b/src/ui/parts/ImagesPart.as
@@ -200,13 +200,9 @@ public class ImagesPart extends UIPart {
 	}
 
 	private function nameChanged():void {
-		var obj:ScratchObj = app.viewedObj();
-		if(!obj.isCostumeNameUsed(nameField.contents())) {
-			obj.currentCostume().costumeName = nameField.contents();
-			(listFrame.contents as MediaPane).refresh();
-		}
-		else
-			nameField.setContents(obj.currentCostume().costumeName);
+		app.runtime.renameCostume(nameField.contents());
+		nameField.setContents(app.viewedObj().currentCostume().costumeName);
+		(listFrame.contents as MediaPane).refresh();
 	}
 
 	private function addNewCostumeButtons():void {