diff --git a/js/display/Display.js b/js/display/Display.js
index 7f2c6506a..085658234 100644
--- a/js/display/Display.js
+++ b/js/display/Display.js
@@ -1740,7 +1740,7 @@ define( function( require ) {
       // If in phet-io brand, a11y is enabled, and the focus is not null
       if ( window.phet && phet.phetio && phet.chipper.accessibility && value ) {
         var node = value.trail.lastNode();
-        assert && assert( node.tandem && node.tandem.isSuppliedAndEnabled(),
+        assert && assert( node.isPhetioInstrumented(),
           'When running phet-io mode, all focusable instances must be instrumented.' );
       }