diff --git a/actionpack/test/activerecord/active_record_store_test.rb b/actionpack/test/activerecord/active_record_store_test.rb
index 34f18806a2..663cd259c8 100644
--- a/actionpack/test/activerecord/active_record_store_test.rb
+++ b/actionpack/test/activerecord/active_record_store_test.rb
@@ -13,6 +13,7 @@ class ActiveRecordStoreTest < ActionController::IntegrationTest
     end
 
     def set_session_value
+      raise "missing session!" unless session
       session[:foo] = params[:foo] || "bar"
       head :ok
     end