diff --git a/lib/utils.js b/lib/utils.js
index 185dc414f4..edea410fdb 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -52,7 +52,7 @@ export function promisifyRoute (fn) {
     })
   }
   let promise = fn()
-  if (!promise || (!(promise instanceof Promise) && (typeof promise.then !== 'function')))
+  if (!promise || (!(promise instanceof Promise) && (typeof promise.then !== 'function'))) {
     promise = Promise.resolve(promise)
   }
   return promise