diff --git a/versioned_docs/version-4.0.0/guides/using-babel.md b/versioned_docs/version-4.0.0/guides/using-babel.md
index 5792d15..df28acc 100644
--- a/versioned_docs/version-4.0.0/guides/using-babel.md
+++ b/versioned_docs/version-4.0.0/guides/using-babel.md
@@ -90,9 +90,9 @@ module.exports = {
       enabled: true,
       // highlight-start
       options: {
-        only: (filePath) => {
+        only: [(filePath) => {
           return filePath.includes("/mocks/") || filePath.includes("/my-folder-to-include/");
-        },
+        }],
       },
       // highlight-end
     },