diff --git a/docs/default-theme-config/README.md b/docs/default-theme-config/README.md
index 257294b0..7f5bcb55 100644
--- a/docs/default-theme-config/README.md
+++ b/docs/default-theme-config/README.md
@@ -374,7 +374,7 @@ But the `refresh` button activates the new service worker immediately.
 ``` js
 module.exports = {
   themeConfig: {
-    serviceWorker {
+    serviceWorker: {
       updatePopup: true | {message: "New content is available.", buttonText: "Refresh"}
     }
   }