diff --git a/lib/common/constants/index.js b/lib/common/constants/index.js
index 86a69d0ea..dc2ea6b46 100644
--- a/lib/common/constants/index.js
+++ b/lib/common/constants/index.js
@@ -1,3 +1,4 @@
+// @flow
 const SECURE: string = 'secure/'
 export const API_PREFIX: string = `/api/manager/`
 export const SECURE_API_PREFIX: string = `${API_PREFIX}${SECURE}`