diff --git a/README.md b/README.md
index d1a088a..b3716dc 100644
--- a/README.md
+++ b/README.md
@@ -36,9 +36,9 @@ npm install @epic-web/client-hints
 
 ## The Problem
 
-Sometimes your server rendered code needs to know something about the client that
-the browser doesn't send. For example, the server might need to know the user's
-preferred language, or whether the user prefers light or dark mode.
+Sometimes your server rendered code needs to know something about the client
+that the browser doesn't send. For example, the server might need to know the
+user's preferred language, or whether the user prefers light or dark mode.
 
 For some of this you should have user preferences which can be persisted in a
 cookie or a database, but you can't do this for first-time visitors. All you can
diff --git a/src/color-scheme.ts b/src/color-scheme.ts
index b0d1437..5639fe6 100644
--- a/src/color-scheme.ts
+++ b/src/color-scheme.ts
@@ -1,4 +1,4 @@
-import { type ClientHint } from './utils'
+import { type ClientHint } from './utils.js'
 
 export const clientHint = {
 	cookieName: 'CH-prefers-color-scheme',
diff --git a/src/index.ts b/src/index.ts
index 11cae37..73dec66 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,4 @@
-import { ClientHint, ClientHintsValue } from './utils'
+import { ClientHint, ClientHintsValue } from './utils.js'
 
 export type { ClientHint }
 
diff --git a/src/reduced-motion.ts b/src/reduced-motion.ts
index fecb734..2a5971c 100644
--- a/src/reduced-motion.ts
+++ b/src/reduced-motion.ts
@@ -1,4 +1,4 @@
-import { type ClientHint } from './utils'
+import { type ClientHint } from './utils.js'
 
 export const clientHint = {
 	cookieName: 'CH-reduced-motion',
diff --git a/src/time-zone.ts b/src/time-zone.ts
index 897718a..d57e867 100644
--- a/src/time-zone.ts
+++ b/src/time-zone.ts
@@ -1,4 +1,4 @@
-import { type ClientHint } from './utils'
+import { type ClientHint } from './utils.js'
 
 export const clientHint = {
 	cookieName: 'CH-time-zone',
diff --git a/test/index.test.ts b/test/index.test.ts
index 78f6bcd..afa02b8 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -1,8 +1,8 @@
 import { test } from 'node:test'
-import { getHintUtils } from '../src'
-import { clientHint as colorSchemeHint } from '../src/color-scheme'
-import { clientHint as timeZoneHint } from '../src/time-zone'
-import { clientHint as reducedMotionHint } from '../src/reduced-motion'
+import { getHintUtils } from '../src/index.js'
+import { clientHint as colorSchemeHint } from '../src/color-scheme.js'
+import { clientHint as timeZoneHint } from '../src/time-zone.js'
+import { clientHint as reducedMotionHint } from '../src/reduced-motion.js'
 import assert from 'node:assert'
 
 test('client script works', () => {