diff --git a/packages/front-end-interview-guidebook/contents/user-interface-components-api-design-principles/en-US.mdx b/packages/front-end-interview-guidebook/contents/user-interface-components-api-design-principles/en-US.mdx
index 7a87d701c..32aa25800 100644
--- a/packages/front-end-interview-guidebook/contents/user-interface-components-api-design-principles/en-US.mdx
+++ b/packages/front-end-interview-guidebook/contents/user-interface-components-api-design-principles/en-US.mdx
@@ -142,7 +142,7 @@ function Slider({ label, value, className, classNameLabel, classNameTrack }) {
         {label}
       </label>
       <input
-        className={clsx('gfe-slider-range', classNameRange)}
+        className={clsx('gfe-slider-range', classNameTrack)}
         id={id}
         type="range"
         value={value}