diff --git a/src/gtin/index.ts b/src/gtin/index.ts
index 880dfa9..c519634 100644
--- a/src/gtin/index.ts
+++ b/src/gtin/index.ts
@@ -5,7 +5,7 @@ import { ProductDTO } from './types'
 export class Gtin extends AppBase {
   public static readonly basePath = 'https://gtin.taakcloud.com'
 
-  getProduct(gtin: string, currency = 'IRR'): Promise<TaakResponse> {
+  getProduct(gtin: number, currency = 'IRR'): Promise<TaakResponse> {
     return this.request<ProductDTO>(
       `/v1/pip/${gtin}/${currency}`,
       {},
diff --git a/src/gtin/types.ts b/src/gtin/types.ts
index bbab22f..2fcb585 100644
--- a/src/gtin/types.ts
+++ b/src/gtin/types.ts
@@ -1,5 +1,5 @@
 export type ProductDTO = {
-  gtin: string
+  gtin: number
   name: string
   nameFa: string
   price: number