diff --git a/controllers/wizard.rb b/controllers/wizard.rb
index f236d772..11e7ce4d 100644
--- a/controllers/wizard.rb
+++ b/controllers/wizard.rb
@@ -15,7 +15,7 @@ class CustomWizard::WizardController < ::ApplicationController
   end
 
   def theme_key
-    wizard['theme_key']
+    wizard ? wizard['theme_key'] : nil
   end
 
   def index