diff --git a/src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js b/src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js
index 6f1eec557..5ee5e788a 100644
--- a/src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js
+++ b/src/data-structures/tree/binary-search-tree/BinarySearchTreeNode.js
@@ -28,8 +28,10 @@ export default class BinarySearchTreeNode extends BinaryTreeNode {
     }
 
     if (value < this.value && this.left) {
+      // Check left nodes.
       return this.left.contains(value);
     } else if (this.right) {
+      // Check right nodes.
       return this.right.contains(value);
     }