diff --git a/more/problem-sets-competitive-programming.md b/more/problem-sets-competitive-programming.md
index 1b5a9720..11000e2b 100644
--- a/more/problem-sets-competitive-programming.md
+++ b/more/problem-sets-competitive-programming.md
@@ -38,6 +38,7 @@
 * [Just another Golf Coding](http://jagc.org)
 * [Kattis](https://open.kattis.com)
 * [LeetCode](https://leetcode.com)
+* [LightOJ](https://lightoj.com)
 * [Microcorruption](https://microcorruption.com/login)
 * [oj.uz](https://oj.uz)
 * [Sphere Online Judge](http://www.spoj.com/contests)