diff --git a/app/controllers/concerns/koi/controller/has_admin_users.rb b/app/controllers/concerns/koi/controller/has_admin_users.rb
index de1dd4b8..0a296c56 100644
--- a/app/controllers/concerns/koi/controller/has_admin_users.rb
+++ b/app/controllers/concerns/koi/controller/has_admin_users.rb
@@ -8,15 +8,24 @@ module HasAdminUsers
       included do
         helper_method :admin_signed_in?
         helper_method :current_admin_user
+
+        # @deprecated use current admin user instead
         helper_method :current_admin
       end
 
       def admin_signed_in?
         current_admin_user.present?
+      rescue ActiveRecord::RecordNotFound
+        false
       end
 
       def current_admin_user
-        @current_admin_user ||= Admin::User.find(session[:admin_user_id]) if session[:admin_user_id].present?
+        return @current_admin_user if instance_variable_defined?(:@current_admin_user)
+        return @current_admin_user = nil unless session.has_key?(:admin_user_id)
+
+        @current_admin_user = Admin::User.find(session[:admin_user_id])
+      ensure
+        session.delete(:admin_user_id) unless @current_admin_user
       end
 
       # @deprecated Use current_admin_user instead