diff --git a/contrib/machine-learning/index.md b/contrib/machine-learning/index.md
index b6945cd..20305dc 100644
--- a/contrib/machine-learning/index.md
+++ b/contrib/machine-learning/index.md
@@ -15,4 +15,5 @@
 - [Logistic Regression](logistic-regression.md)
 - [Types_of_Cost_Functions](cost-functions.md)
 - [Clustering](clustering.md)
+- [Hierarchical Clustering](hierarchical-clustering.md)
 - [Grid Search](grid-search.md)