diff --git a/lib/core/tree.js b/lib/core/tree.js
index 84293816721..e7b960cb2b3 100644
--- a/lib/core/tree.js
+++ b/lib/core/tree.js
@@ -40,6 +40,7 @@ class TstNode {
   /**
    * @param {string} key
    * @param {any} value
+   * @returns {void}
    */
   add (key, value) {
     const length = key.length
@@ -91,7 +92,7 @@ class TstNode {
     const keylength = key.length
     let index = 0
     /**
-     * @type {TstNode}
+     * @type {TstNode|null}
      */
     let node = this
     while (node !== null && index < keylength) {
@@ -127,6 +128,7 @@ class TernarySearchTree {
   /**
    * @param {string} key
    * @param {any} value
+   * @returns {void}
    * */
   insert (key, value) {
     if (this.node === null) {
@@ -138,7 +140,7 @@ class TernarySearchTree {
 
   /**
    * @param {Uint8Array} key
-   * @return {any}
+   * @returns {any}
    */
   lookup (key) {
     return this.node?.search(key)?.value ?? null