diff --git a/src/bin/initialize-account-theme/updateAccountThemeImplementationInConfig.ts b/src/bin/initialize-account-theme/updateAccountThemeImplementationInConfig.ts
index 1c60ef03..65b3ba39 100644
--- a/src/bin/initialize-account-theme/updateAccountThemeImplementationInConfig.ts
+++ b/src/bin/initialize-account-theme/updateAccountThemeImplementationInConfig.ts
@@ -5,6 +5,7 @@ import * as fs from "fs";
 import chalk from "chalk";
 import { z } from "zod";
 import { id } from "tsafe/id";
+import { is } from "tsafe/is";
 
 export type BuildContextLike = {
     bundler: BuildContext["bundler"];
@@ -83,6 +84,8 @@ export function updateAccountThemeImplementationInConfig(params: {
 
                     zParsedPackageJson.parse(parsedPackageJson);
 
+                    assert(is<ParsedPackageJson>(parsedPackageJson));
+
                     return parsedPackageJson;
                 })();