diff --git a/app/controllers/concerns/authentication.rb b/app/controllers/concerns/authentication.rb
index 1ce96c7a2..89871a9f5 100644
--- a/app/controllers/concerns/authentication.rb
+++ b/app/controllers/concerns/authentication.rb
@@ -8,6 +8,8 @@ module Authentication
     before_action :require_authentication
     helper_method :authenticated?
 
+    etag { Current.session.id if authenticated? }
+
     include LoginHelper
   end