diff --git a/curriculum/challenges/english/blocks/lab-leap-year-calculator/66c06fad3475cd92421b9ac2.md b/curriculum/challenges/english/blocks/lab-leap-year-calculator/66c06fad3475cd92421b9ac2.md
index b640ada0857..f2fdc97ebd6 100644
--- a/curriculum/challenges/english/blocks/lab-leap-year-calculator/66c06fad3475cd92421b9ac2.md
+++ b/curriculum/challenges/english/blocks/lab-leap-year-calculator/66c06fad3475cd92421b9ac2.md
@@ -44,6 +44,9 @@ You should declare a variable `year` and assign it a value to check if it is a l
 
 ```js
 assert.isDefined(year);
+assert.isNumber(year);
+assert.isAtLeast(year, 0);
+assert.isTrue(Number.isInteger(year));
 ```
 
 The `year` variable shouldn't be empty.