diff --git a/shield/kibana/index.js b/shield/kibana/index.js
index 7d7dc789544..9100a16dfe3 100644
--- a/shield/kibana/index.js
+++ b/shield/kibana/index.js
@@ -9,7 +9,7 @@ module.exports = (kibana) => new kibana.Plugin({
   config(Joi) {
     return Joi.object({
       enabled: Joi.boolean().default(true),
-      encryptionKey: Joi.string().default('secret'),
+      encryptionKey: Joi.string().required(),
       sessionTimeout: Joi.number().default(30 * 60 * 1000)
     }).default()
   },