diff --git a/Scripts/AnimationTimeline.gd b/Scripts/AnimationTimeline.gd
index d7d3c55..fb8a1dc 100644
--- a/Scripts/AnimationTimeline.gd
+++ b/Scripts/AnimationTimeline.gd
@@ -264,8 +264,9 @@ func _on_MergeDownLayer_pressed() -> void:
 	Global.undo_redo.add_undo_property(Global, "layers", Global.layers)
 	Global.undo_redo.add_undo_property(Global, "current_layer", Global.current_layer)
 
-	Global.undo_redo.add_undo_method(Global, "undo", [Global.canvas])
-	Global.undo_redo.add_do_method(Global, "redo", [Global.canvas])
+	for c in Global.canvases:
+		Global.undo_redo.add_undo_method(Global, "undo", [c])
+		Global.undo_redo.add_do_method(Global, "redo", [c])
 	Global.undo_redo.commit_action()
 
 func _on_OpacitySlider_value_changed(value) -> void: