diff --git a/js/ComboBoxItem.js b/js/ComboBoxItem.js
index eba871ff..7774982f 100644
--- a/js/ComboBoxItem.js
+++ b/js/ComboBoxItem.js
@@ -22,6 +22,7 @@ define( require => {
     constructor( node, value, options ) {
 
       assert && assert( node instanceof Node, 'invalid node: ' + node );
+      assert && assert( !node.accessibleContent, 'accessibleContent is set by ComboBox, use options.a11yLabel' );
 
       options = _.extend( {
 
diff --git a/js/ComboBoxListItemNode.js b/js/ComboBoxListItemNode.js
index 05507f79..0cdd59ee 100644
--- a/js/ComboBoxListItemNode.js
+++ b/js/ComboBoxListItemNode.js
@@ -29,8 +29,6 @@ define( require => {
 
       assert && assert( item instanceof ComboBoxItem );
 
-      // TODO sun#314 assert you may not be allowed to have accessibleContent on the item.node, since we set the innerContent on this LI
-
       options = _.extend( {
 
         cursor: 'pointer',
@@ -82,8 +80,8 @@ define( require => {
       this.highlightRectangle = highlightRectangle;
       this.highlightFill = options.highlightFill;
 
-      // the focus highlight wraps around the entire item rectangle
-      itemNodeWrapper.focusHighlight = Shape.bounds( itemNodeWrapper.parentToLocalBounds( this.localBounds ) );
+      // focus highlight is fitted to this Node's bounds, so that it doesn't overlap items above/below in the list box
+      this.focusHighlight = Shape.bounds( this.localBounds );
     }
 
     /**