diff --git a/problem-sets-competitive-programming.md b/problem-sets-competitive-programming.md
index e3967ddfb901f0573fdf118540a06e1ab612b643..339949d0cae9a003cad7abd6afa075940af5c048 100644
--- a/problem-sets-competitive-programming.md
+++ b/problem-sets-competitive-programming.md
@@ -35,7 +35,7 @@
 * [ProblemBook.NET](http://problembook.net/content/en/index.html)
 * [Project Euler](https://projecteuler.net/)
 * [Python Practice Projects](http://pythonpracticeprojects.com/)
-* [Rosalind](rosalind.info/problems/locations/)
+* [Rosalind](http://rosalind.info/problems/locations/)
 * [Sphere Online Judge](http://www.spoj.com/)
 * [TalentBuddy](http://www.talentbuddy.co/)
 * [Timus Online Judge](http://acm.timus.ru/)