diff --git a/lib/config/default.js b/lib/config/default.js
index b4b7e846..7c5e9b33 100644
--- a/lib/config/default.js
+++ b/lib/config/default.js
@@ -14,7 +14,7 @@ module.exports = {
   hsts: {
     enable: true,
     maxAgeSeconds: 60 * 60 * 24 * 365,
-    includeSubdomains: true,
+    includeSubdomains: false,
     preload: true
   },
   csp: {