diff --git a/seed/challenges/html5-and-css.json b/seed/challenges/html5-and-css.json
index 3d0f52b42e7..e0ad812245b 100644
--- a/seed/challenges/html5-and-css.json
+++ b/seed/challenges/html5-and-css.json
@@ -2739,7 +2739,7 @@
         "An element's <code>margin</code> controls the amount of space between an element's <code>border</code> and surrounding elements.",
         "If you set an element's <code>margin</code> to a negative value, the element will grow larger.",
         "Try to set the <code>margin</code> to a negative value like the one for the red box.",
-        "Change the <code>margin</code> of the green box to a negative value, so it fills the entire horizontal width of the yellow box around it."
+        "Change the <code>margin</code> of the green box to -15 pixels, so it fills the entire horizontal width of the yellow box around it."
       ],
       "tests": [
         "assert($('.green-box').css('margin-top') === '-15px', 'Your <code>green-box</code> class should give elements -15px of margin.')"