diff --git a/challenges/08-coding-interview-questions-and-take-home-assignments/coding-interview-data-structure-questions.json b/challenges/08-coding-interview-questions-and-take-home-assignments/coding-interview-data-structure-questions.json
index b855c353f9..43520b8492 100644
--- a/challenges/08-coding-interview-questions-and-take-home-assignments/coding-interview-data-structure-questions.json
+++ b/challenges/08-coding-interview-questions-and-take-home-assignments/coding-interview-data-structure-questions.json
@@ -230,7 +230,8 @@
         "<blockquote>var set = new Object();<br>set.foo = true;<br>// See if foo exists in our set:<br>console.log(set.foo) // true</blockquote>",
         "In the next few exercises, we will build a full featured Set from scratch.",
         "For this exercise, create a function that will add a value to our set collection as long as the value does not already exist in the set. For example:",
-        "<blockquote>this.add = function(element) {<br>  //some code to add value to the set<br>}</blockquote>"
+        "<blockquote>this.add = function(element) {<br>  //some code to add value to the set<br>}</blockquote>",
+        "The function should return <code>true</code> if the value is successfully added and <code>false</code> otherwise."
       ],
       "challengeSeed": [
         "function Set() {",
@@ -250,7 +251,9 @@
       ],
       "tests": [
         "assert((function(){var test = new Set(); return (typeof test.add === 'function')}()), 'message: Your <code>Set</code> class should have a <code>add</code> method.');",
-        "assert((function(){var test = new Set(); test.add('a'); test.add('b'); test.add('a'); var vals = test.values(); console.log(vals); return (vals[0] === 'a' && vals[1] === 'b' && vals.length === 2)}()), 'message: Your <code>Set</code> should not add duplicate values.');"
+        "assert((function(){var test = new Set(); test.add('a'); test.add('b'); test.add('a'); var vals = test.values(); console.log(vals); return (vals[0] === 'a' && vals[1] === 'b' && vals.length === 2)}()), 'message: Your <code>Set</code> should not add duplicate values.');",
+        "assert((function(){var test = new Set(); var result = test.add('a'); return (result != undefined) && (result === true);}()), 'message: Your <code>Set</code> should return <code>true</code> when a value has been successfully added.');",
+        "assert((function(){var test = new Set(); test.add('a'); var result = test.add('a'); return (result != undefined) && (result === false);}()), 'message: Your <code>Set</code> should return <code>false</code> when the user tries to add a duplicate value.');"
       ],
       "type": "waypoint",
       "solutions": [],