diff --git a/app/controllers/concerns/authenticatable.rb b/app/controllers/concerns/authenticatable.rb
index 9314cc9..492f5ce 100644
--- a/app/controllers/concerns/authenticatable.rb
+++ b/app/controllers/concerns/authenticatable.rb
@@ -8,6 +8,6 @@ module Authenticatable
   private
 
   def authenticate_user
-    Current.user = User.find_by(id: session[:current_user_id])
+    Current.user = User.find_by(id: session[:current_user_id]) || GuestUser.new
   end
 end
diff --git a/app/views/layouts/application.html.erb b/app/views/layouts/application.html.erb
index fb838b8..a4b84df 100644
--- a/app/views/layouts/application.html.erb
+++ b/app/views/layouts/application.html.erb
@@ -19,7 +19,7 @@
         <li class="mr-6"><%= link_to "Credit Card Bills", credit_card_bills_path, class: "text-white" %></li>
         <li class="mr-6"><%= link_to "Incomes", incomes_path, class: "text-white" %></li>
         <li class="mr-6"><%= link_to "Members", members_path, class: "text-white" %></li>
-        <% if Current.user %>
+        <% if Current.user.registered? %>
           <li class="mr-6"><%= link_to "Log out", session_path, data: {turbo_method: :delete}, class: "text-white" %></li>
         <% else %>
           <li class="mr-6"><%= link_to "Log in", new_session_path, class: "text-white" %></li>