diff --git a/test/lib/construct.test.ts b/test/lib/construct.test.ts
index 09ee325..9904619 100644
--- a/test/lib/construct.test.ts
+++ b/test/lib/construct.test.ts
@@ -261,14 +261,14 @@ describe('lib/construct', () => {
 
   it('should dedupe class names where required', () => {
     const parameters: ConstructOptions = {
-      attrs: { isPrimary: true },
+      attrs: { className: 'heading', isPrimary: true },
       classNames: 'heading',
       styles: styles,
       target: 'h1',
     };
 
     render(createElement(construct(parameters), { isPrimary: true }));
-    expect(screen.getByRole('heading')).toHaveClass('heading heading--primary');
+    expect(screen.getByRole('heading').className).toMatch('heading heading--primary');
   });
 
   it('should convert `style` props to a dynamically rendered class name', () => {