diff --git a/package.json b/package.json
index d3d29e5..361aa81 100644
--- a/package.json
+++ b/package.json
@@ -5,6 +5,7 @@
   "main": "main.js",
   "scripts": {
     "build": "node esbuild.config.mjs production",
+    "check:build-artifacts": "node scripts/check-build-artifacts.mjs",
     "dev": "node esbuild.config.mjs watch",
     "typecheck": "tsc --noEmit",
     "lint": "biome check main.ts src/",
diff --git a/scripts/check-build-artifacts.mjs b/scripts/check-build-artifacts.mjs
new file mode 100644
index 0000000..1b8a032
--- /dev/null
+++ b/scripts/check-build-artifacts.mjs
@@ -0,0 +1,19 @@
+import { execFileSync } from 'node:child_process';
+
+function diffMainJs() {
+  return execFileSync('git', ['diff', '--', 'main.js'], { encoding: 'utf8' });
+}
+
+const before = diffMainJs();
+
+execFileSync('npm', ['run', 'build'], { stdio: 'inherit' });
+
+const after = diffMainJs();
+
+if (after !== before) {
+  console.error('\nmain.js is not in sync with the TypeScript source.');
+  console.error('Run `npm run build` and include the updated main.js in the same change.');
+  process.exit(1);
+}
+
+console.log('main.js is in sync with the TypeScript source.');