diff --git a/src/data-structures/binary-tree/binary-tree.ts b/src/data-structures/binary-tree/binary-tree.ts
index 103dc4e..44ece16 100644
--- a/src/data-structures/binary-tree/binary-tree.ts
+++ b/src/data-structures/binary-tree/binary-tree.ts
@@ -1727,7 +1727,7 @@ export class BinaryTree<V = any, N extends BinaryTreeNode<V, N> = BinaryTreeNode
 
   /**
    * The `print` function is used to display a binary tree structure in a visually appealing way.
-   * @param {N | null | undefined} root - The `root` parameter is of type `BTNKey | N | null |
+   * @param {N | null | undefined} beginRoot - The `root` parameter is of type `BTNKey | N | null |
    * undefined`. It represents the root node of a binary tree. The root node can have one of the
    * following types:
    */
diff --git a/src/data-structures/binary-tree/rb-tree.ts b/src/data-structures/binary-tree/rb-tree.ts
index 268e742..95f317d 100644
--- a/src/data-structures/binary-tree/rb-tree.ts
+++ b/src/data-structures/binary-tree/rb-tree.ts
@@ -103,11 +103,16 @@ export class RedBlackTree<V = any, N extends RedBlackTreeNode<V, N> = RedBlackTr
 
     while (x !== this.NIL) {
       y = x;
-      if (x && node.key < x.key) {
-        x = x.left;
-      } else {
-        x = x?.right;
+      if (x) {
+        if (node.key < x.key) {
+          x = x.left;
+        } else if (node.key > x.key){
+          x = x?.right;
+        } else {
+          return;
+        }
       }
+
     }
 
     node.parent = y;
diff --git a/src/types/helpers.ts b/src/types/common.ts
similarity index 100%
rename from src/types/helpers.ts
rename to src/types/common.ts
diff --git a/src/types/index.ts b/src/types/index.ts
index 020d17c..2530dca 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -1,3 +1,3 @@
 export * from './data-structures';
-export * from './helpers';
+export * from './common';
 export * from './utils';
diff --git a/test/unit/data-structures/binary-tree/rb-tree.test.ts b/test/unit/data-structures/binary-tree/rb-tree.test.ts
index b31c168..eb13e21 100644
--- a/test/unit/data-structures/binary-tree/rb-tree.test.ts
+++ b/test/unit/data-structures/binary-tree/rb-tree.test.ts
@@ -487,4 +487,21 @@ describe('RedBlackTree', () => {
     }
     isDebug && console.log(performance.now() - cS);
   });
+
+  it('duplicates', () => {
+    tree.addMany([9,8,7,8,8,8,2,3,6,5,5,4]);
+    tree.print();
+
+    expect(tree.size).toBe(8);
+    expect(tree.isBST()).toBe(true);
+    expect(tree.isAVLBalanced()).toBe(true);
+    tree.addMany([10, 5, 2, 11]);
+    expect(tree.size).toBe(10);
+    expect(tree.isBST()).toBe(true);
+    expect(tree.isAVLBalanced()).toBe(true);
+
+    tree.clear();
+    tree.addMany([10, 20, 30, 40, 50, 60])
+    expect(tree.isAVLBalanced()).toBe(false);
+  })
 });