diff --git a/seed/challenges/01-front-end-development-certification/basic-javascript.json b/seed/challenges/01-front-end-development-certification/basic-javascript.json
index fd2bbaa16c..5336c09437 100644
--- a/seed/challenges/01-front-end-development-certification/basic-javascript.json
+++ b/seed/challenges/01-front-end-development-certification/basic-javascript.json
@@ -3539,7 +3539,8 @@
         "assert((function(z){if(z.hasOwnProperty(\"name\") && z.name !== undefined && typeof(z.name) === \"string\"){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>name</code> and it should be a <code>string</code>.');",
         "assert((function(z){if(z.hasOwnProperty(\"legs\") && z.legs !== undefined && typeof(z.legs) === \"number\"){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>legs</code> and it should be a <code>number</code>.');",
         "assert((function(z){if(z.hasOwnProperty(\"tails\") && z.tails !== undefined && typeof(z.tails) === \"number\"){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>tails</code> and it should be a <code>number</code>.');",
-        "assert((function(z){if(z.hasOwnProperty(\"friends\") && z.friends !== undefined && Array.isArray(z.friends)){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>friends</code> and it should be an <code>array</code>.');"
+        "assert((function(z){if(z.hasOwnProperty(\"friends\") && z.friends !== undefined && Array.isArray(z.friends)){return true;}else{return false;}})(myDog), 'message: <code>myDog</code> should contain the property <code>friends</code> and it should be an <code>array</code>.');",
+        "assert((function(z){return Object.keys(z).length === 4;})(myDog), 'message: <code>myDog</code> should only contain all the given properties.');"
       ],
       "challengeSeed": [
         "// Example",
@@ -3553,10 +3554,10 @@
         "// Only change code below this line.",
         "",
         "var myDog = {",
-        "",
-        "",
-        "",
-        "",
+        "  ",
+        "  ",
+        "  ",
+        "  ",
         "};"
       ],
       "tail": [