diff --git a/src/options.ts b/src/options.ts
index 9f1f0cb2..21de0859 100644
--- a/src/options.ts
+++ b/src/options.ts
@@ -22,7 +22,7 @@ async function init() {
 
     // selected tab
     if (location.hash != "") {
-        const substr = location.hash.substring(1);
+        const substr = location.hash.slice(1);
         let menuItem = document.querySelector(`[data-for='${substr}']`);
         if (menuItem == null)
             menuItem = document.querySelector(`[data-for='behavior']`);
diff --git a/src/utils/pageUtils.ts b/src/utils/pageUtils.ts
index 28ac37d8..8f484d73 100644
--- a/src/utils/pageUtils.ts
+++ b/src/utils/pageUtils.ts
@@ -43,7 +43,7 @@ function findValidElementFromGenerator<T>(objects: T[] | NodeListOf<HTMLElement>
 }
 
 export function getHashParams(): Record<string, unknown> {
-    const windowHash = window.location.hash.substr(1);
+    const windowHash = window.location.hash.slice(1);
     if (windowHash) {
         const params: Record<string, unknown> = windowHash.split('&').reduce((acc, param) => {
             const [key, value] = param.split('=');