diff --git a/lib/index.js b/lib/index.js
index 53b604c..d9234c4 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -6,7 +6,6 @@
  * @typedef {import('./parse-argv.js').State} State
  */
 
-import assert from 'node:assert/strict'
 import process from 'node:process'
 import stream from 'node:stream'
 import {fileURLToPath} from 'node:url'
@@ -144,10 +143,14 @@ export function args(options) {
         ? fileURLToPath(state.engine.cwd)
         : state.engine.cwd
 
-    assert(typeof cwd === 'string', '`cwd` is defined')
-
     watcher = chokidar
-      .watch(urls, {cwd, ignoreInitial: true})
+      .watch(
+        urls,
+        // @ts-expect-error: chokidar types are wrong w/
+        // `exactOptionalPropertyTypes`,
+        // `cwd` can be `undefined`.
+        {cwd, ignoreInitial: true}
+      )
       .on('error', done)
       .on('change', function (filePath) {
         state.engine.files = [filePath]