diff --git a/lib/config/hackmdEnvironment.js b/lib/config/hackmdEnvironment.js
index ecdd9a513..76e413612 100644
--- a/lib/config/hackmdEnvironment.js
+++ b/lib/config/hackmdEnvironment.js
@@ -24,7 +24,6 @@ module.exports = {
   allowAnonymous: toBooleanConfig(process.env.HMD_ALLOW_ANONYMOUS),
   allowAnonymousEdits: toBooleanConfig(process.env.HMD_ALLOW_ANONYMOUS_EDITS),
   allowFreeURL: toBooleanConfig(process.env.HMD_ALLOW_FREEURL),
-  requireFreeURLAuthentication: toBooleanConfig(process.env.HMD_REQUIRE_FREEURL_AUTH),
   defaultPermission: process.env.HMD_DEFAULT_PERMISSION,
   dbURL: process.env.HMD_DB_URL,
   sessionSecret: process.env.HMD_SESSION_SECRET,