diff --git a/js/phet-io/atomic-interactions-overrides.js b/js/phet-io/atomic-interactions-overrides.js
index 5a34c95..30c8604 100644
--- a/js/phet-io/atomic-interactions-overrides.js
+++ b/js/phet-io/atomic-interactions-overrides.js
@@ -7,6 +7,9 @@ window.phet.preloads.phetio.phetioElementsOverrides =
   "atomicInteractions.atomicInteractionsScreen.model.movableAtom.positionProperty": {
     "phetioFeatured": true
   },
+  "atomicInteractions.atomicInteractionsScreen.model.movableAtom.radiusProperty": {
+    "phetioFeatured": true
+  },
   "atomicInteractions.atomicInteractionsScreen.model.movableAtom.velocityProperty": {
     "phetioFeatured": true
   },