diff --git a/config/environments/production.rb b/config/environments/production.rb
index 0c91e600..879cc797 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -145,5 +145,5 @@ Rails.application.configure do
   config.active_record.dump_schema_after_migration = false
 
   # Set the relative url root for deployment to a subdirectory.
-  config.relative_url_root = ENV['RELATIVE_URL_ROOT'].present? ? ENV['RELATIVE_URL_ROOT'] : "/b"
+  config.relative_url_root = ENV['RELATIVE_URL_ROOT'] || "/b" if ENV['RELATIVE_URL_ROOT'] != "/"
 end