diff --git a/js/macro/view/MacroScreenView.ts b/js/macro/view/MacroScreenView.ts
index fa19691c..4b3027d2 100644
--- a/js/macro/view/MacroScreenView.ts
+++ b/js/macro/view/MacroScreenView.ts
@@ -98,7 +98,7 @@ export default class MacroScreenView extends ScreenView {
     } );
 
     // pH meter
-    const pHMeter = model.pHMeter!;
+    const pHMeter = model.pHMeter;
     assert && assert( pHMeter );
     const pHMeterNode = new MacroPHMeterNode( pHMeter, model.solution, model.dropper,
       solutionNode, dropperFluidNode, waterFluidNode, drainFluidNode, modelViewTransform, {