diff --git a/js/common/view/GeometricOpticsRulerNode.ts b/js/common/view/GeometricOpticsRulerNode.ts
index 2bec5dfd..fe80ef72 100644
--- a/js/common/view/GeometricOpticsRulerNode.ts
+++ b/js/common/view/GeometricOpticsRulerNode.ts
@@ -74,6 +74,7 @@ class GeometricOpticsRulerNode extends Node {
     this.toolboxBounds = Bounds2.NOTHING; // to be set later via setToolboxBounds
 
     // Create a RulerNode subcomponent to match zoomScale.
+    //TODO https://github.com/phetsims/geometric-optics/issues/133 this is listener also depends on zoomTransformProperty, so there's a problematic ordering dependency there
     zoomScaleProperty.link( zoomScale => {
 
       // update model length, so that view length remains the same