diff --git a/challenges/01-front-end-development-certification/advanced-bonfires.json b/challenges/01-front-end-development-certification/advanced-bonfires.json
index e720ebcf905..c7c90a3693e 100644
--- a/challenges/01-front-end-development-certification/advanced-bonfires.json
+++ b/challenges/01-front-end-development-certification/advanced-bonfires.json
@@ -105,6 +105,10 @@
       "tests": [
         "assert.sameMembers(sym([1, 2, 3], [5, 2, 1, 4]), [3, 4, 5], 'message: <code>sym([1, 2, 3], [5, 2, 1, 4])</code> should return <code>[3, 4, 5]</code>.');",
         "assert.equal(sym([1, 2, 3], [5, 2, 1, 4]).length, 3, 'message: <code>sym([1, 2, 3], [5, 2, 1, 4])</code> should contain only three elements.');",
+        "assert.sameMembers(sym([1, 2, 3, 3], [5, 2, 1, 4]), [3, 4, 5], 'message: <code>sym([1, 2, 3, 3], [5, 2, 1, 4])</code> should return <code>[3, 4, 5]</code>.');",
+        "assert.equal(sym([1, 2, 3, 3], [5, 2, 1, 4]).length, 3, 'message: <code>sym([1, 2, 3, 3], [5, 2, 1, 4])</code> should contain only three elements.');",
+        "assert.sameMembers(sym([1, 2, 3], [5, 2, 1, 4, 5]), [3, 4, 5], 'message: <code>sym([1, 2, 3], [5, 2, 1, 4, 5])</code> should return <code>[3, 4, 5]</code>.');",
+        "assert.equal(sym([1, 2, 3], [5, 2, 1, 4, 5]).length, 3, 'message: <code>sym([1, 2, 3], [5, 2, 1, 4, 5])</code> should contain only three elements.');",
         "assert.sameMembers(sym([1, 2, 5], [2, 3, 5], [3, 4, 5]), [1, 4, 5], 'message: <code>sym([1, 2, 5], [2, 3, 5], [3, 4, 5])</code> should return <code>[1, 4, 5]</code>');",
         "assert.equal(sym([1, 2, 5], [2, 3, 5], [3, 4, 5]).length, 3, 'message: <code>sym([1, 2, 5], [2, 3, 5], [3, 4, 5])</code> should contain only three elements.');",
         "assert.sameMembers(sym([1, 1, 2, 5], [2, 2, 3, 5], [3, 4, 5, 5]), [1, 4, 5], 'message: <code>sym([1, 1, 2, 5], [2, 2, 3, 5], [3, 4, 5, 5])</code> should return <code>[1, 4, 5]</code>.');",