diff --git a/challenges/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting.json b/challenges/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting.json
index 5ed6f0b580..c2d3c0323a 100644
--- a/challenges/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting.json
+++ b/challenges/02-javascript-algorithms-and-data-structures/basic-algorithm-scripting.json
@@ -392,7 +392,8 @@
         "assert(repeatStringNumTimes(\"abc\", 4) === \"abcabcabcabc\", 'message: <code>repeatStringNumTimes(\"abc\", 4)</code> should return <code>\"abcabcabcabc\"</code>.');",
         "assert(repeatStringNumTimes(\"abc\", 1) === \"abc\", 'message: <code>repeatStringNumTimes(\"abc\", 1)</code> should return <code>\"abc\"</code>.');",
         "assert(repeatStringNumTimes(\"*\", 8) === \"********\", 'message: <code>repeatStringNumTimes(\"*\", 8)</code> should return <code>\"********\"</code>.');",
-        "assert(repeatStringNumTimes(\"abc\", -2) === \"\", 'message: <code>repeatStringNumTimes(\"abc\", -2)</code> should return <code>\"\"</code>.');"
+        "assert(repeatStringNumTimes(\"abc\", -2) === \"\", 'message: <code>repeatStringNumTimes(\"abc\", -2)</code> should return <code>\"\"</code>.');",
+        "assert(!/\\.repeat/g.test(code), 'message: The built-in <code>repeat()</code>-method should not be used');"
       ],
       "type": "bonfire",
       "isRequired": true,
@@ -899,4 +900,4 @@
       }
     }
   ]
-}
\ No newline at end of file
+}