diff --git a/learn/tasks/cascade/cascade-download.html b/learn/tasks/cascade/cascade-download.html
index 6e0e65c3..a902ac38 100644
--- a/learn/tasks/cascade/cascade-download.html
+++ b/learn/tasks/cascade/cascade-download.html
@@ -8,7 +8,7 @@
       body {
         background-color: #fff;
         color: #333;
-        font: 1.2em / 1.5 Helvetica Neue, Helvetica, Arial, sans-serif;
+        font: 1.2em / 1.5 "Helvetica Neue", Helvetica, Arial, sans-serif;
         padding: 1em;
         margin: 0;
       }