diff --git a/lib/src/package.json b/lib/src/package.json
index 6b47367..70eb48a 100644
--- a/lib/src/package.json
+++ b/lib/src/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@gxc-solutions/lett-js",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "main": "index.js",
   "author": "GXC Solutions",
   "publishConfig": {
diff --git a/lib/src/web-api/uuidv4.ts b/lib/src/web-api/uuidv4.ts
index aa28175..c38b4fb 100644
--- a/lib/src/web-api/uuidv4.ts
+++ b/lib/src/web-api/uuidv4.ts
@@ -1,4 +1,6 @@
-export const uuidv4 = () => {
+export type UUID_V4 = `${string}-${string}-${string}-${string}-${string}`;
+
+export const uuidv4 = (): UUID_V4 => {
   if (crypto.randomUUID == null) {
     "10000000-1000-4000-8000-100000000000".replace(/[018]/g, (c) =>
       // eslint-disable-next-line no-bitwise