diff --git a/apps/page/src/service-worker-build.test.ts b/apps/page/src/service-worker-build.test.ts
new file mode 100644
index 00000000..5d553180
--- /dev/null
+++ b/apps/page/src/service-worker-build.test.ts
@@ -0,0 +1,16 @@
+import { readFile } from 'node:fs/promises';
+import path from 'node:path';
+
+import { describe, expect, test } from 'bun:test';
+
+const SERVICE_WORKER_PATH = path.join(import.meta.dir, 'service-worker.ts');
+const WASM_PLACEHOLDER = '// WASM_PLACEHOLDER - will be replaced at build time';
+
+describe('service worker build integration', () => {
+  test('keeps the asset list valid when injecting the wasm filename', async () => {
+    const serviceWorkerContent = await readFile(SERVICE_WORKER_PATH, 'utf8');
+    const builtServiceWorkerContent = serviceWorkerContent.replace(WASM_PLACEHOLDER, '`${BASE_PATH}/websl_bg.wasm`,');
+
+    expect(builtServiceWorkerContent).toMatch(/`\$\{BASE_PATH\}\/manifest\.json`,\s+`\$\{BASE_PATH\}\/websl_bg\.wasm`,/);
+  });
+});
diff --git a/apps/page/src/service-worker.ts b/apps/page/src/service-worker.ts
index 58fa1be5..cd3ee2ff 100644
--- a/apps/page/src/service-worker.ts
+++ b/apps/page/src/service-worker.ts
@@ -26,7 +26,7 @@ const ASSETS_TO_CACHE = [
   `${BASE_PATH}/favicon.svg`,
   `${BASE_PATH}/index.js`,
   `${BASE_PATH}/embed.js`,
-  `${BASE_PATH}/manifest.json`
+  `${BASE_PATH}/manifest.json`,
   // WASM_PLACEHOLDER - will be replaced at build time
 ];