diff --git a/index.ts b/index.ts
index 8248c49..c967b78 100644
--- a/index.ts
+++ b/index.ts
@@ -1,2 +1,2 @@
-export * from './src/extensions';
-export * from './src/spec_generated';
+export * from './src/extensions.js';
+export * from './src/spec_generated.js';
diff --git a/src/extensions.ts b/src/extensions.ts
index 36c584f..8d7c027 100644
--- a/src/extensions.ts
+++ b/src/extensions.ts
@@ -15,7 +15,7 @@ import {
   CheckoutWithFulfillmentUpdateRequestSchema,
   OrderSchema,
   PaymentCredentialSchema,
-} from "./spec_generated";
+} from "./spec_generated.js";
 
 export const ExtendedPaymentCredentialSchema = PaymentCredentialSchema.extend({
   token: z.string().optional(),