diff --git a/package.scripts.js b/package.scripts.js
index 7877669..fad4d57 100644
--- a/package.scripts.js
+++ b/package.scripts.js
@@ -14,6 +14,7 @@ module.exports = {
       _default: "bsm ~.*",
       eslint: "eslint .",
       prettier: "prettier -c .",
+      typescript: "tsc --noEmit",
     },
   },
 };
diff --git a/src/common.ts b/src/common.ts
index ee2d52b..b94912f 100644
--- a/src/common.ts
+++ b/src/common.ts
@@ -238,7 +238,7 @@ export interface ISalesInvoiceCreate {
     description: string;
     period?: string;
     price: string;
-    amount: number;
+    amount?: number | string;
     tax_rate_id: string;
     ledger_account_id: string;
     project_id?: string;