diff --git a/packages/cosmic-proto/test/helpers.test-d.ts b/packages/cosmic-proto/test/helpers.test-d.ts
index b098aa220292..22b0d974ac40 100644
--- a/packages/cosmic-proto/test/helpers.test-d.ts
+++ b/packages/cosmic-proto/test/helpers.test-d.ts
@@ -1,5 +1,5 @@
 import { expectType } from 'tsd';
-import { typedJson } from '../src/helpers.ts';
+import { typedJson } from '../src/helpers.js';
 import type { ResponseTo } from '../src/helpers.ts';
 
 // MsgSend