diff --git a/src/data-structures/tree/tree.ts b/src/data-structures/tree/tree.ts
index be01002..b2167d6 100644
--- a/src/data-structures/tree/tree.ts
+++ b/src/data-structures/tree/tree.ts
@@ -47,10 +47,8 @@ export class TreeNode<V = any> {
   }
 
   getHeight() {
-    // eslint-disable-next-line @typescript-eslint/no-this-alias
-    const beginRoot = this;
-    let maxDepth = 1;
-    if (beginRoot) {
+    let maxDepth = 0;
+    if (this) {
       const bfs = (node: TreeNode<V>, level: number) => {
         if (level > maxDepth) {
           maxDepth = level;
@@ -62,7 +60,7 @@ export class TreeNode<V = any> {
           }
         }
       };
-      bfs(beginRoot, 1);
+      bfs(this, 0);
     }
     return maxDepth;
   }
diff --git a/test/unit/data-structures/tree/tree.test.ts b/test/unit/data-structures/tree/tree.test.ts
index 1ea5e47..5cda52c 100644
--- a/test/unit/data-structures/tree/tree.test.ts
+++ b/test/unit/data-structures/tree/tree.test.ts
@@ -29,11 +29,11 @@ describe('TreeNode', () => {
     child1.addChildren([grandchild1]);
     child2.addChildren([grandchild2]);
 
-    expect(rootNode.getHeight()).toBe(3); // Height of the tree should be 3
+    expect(rootNode.getHeight()).toBe(2); // Height of the tree should be 2
   });
 
   it('should handle nodes without children when calculating height', () => {
     const rootNode = new TreeNode<string>('1', 'Root Node');
-    expect(rootNode.getHeight()).toBe(1); // Height of a single node should be 1
+    expect(rootNode.getHeight()).toBe(0); // Height of a single node should be 0
   });
 });