diff --git a/lib/discourse_topic_voting/categories_controller_extension.rb b/lib/discourse_topic_voting/categories_controller_extension.rb
index 34e1bb1..f208dbf 100644
--- a/lib/discourse_topic_voting/categories_controller_extension.rb
+++ b/lib/discourse_topic_voting/categories_controller_extension.rb
@@ -4,7 +4,7 @@ module DiscourseTopicVoting
   module CategoriesControllerExtension
     def category_params
       @vote_enabled ||=
-        !!ActiveRecord::Type::Boolean.new.cast(params[:custom_fields][:enable_topic_voting])
+        !!ActiveRecord::Type::Boolean.new.cast(params&.[](:custom_fields)&.[](:enable_topic_voting))
 
       category_params = super
 
diff --git a/spec/requests/categories_controller_spec.rb b/spec/requests/categories_controller_spec.rb
index f00e387..d8ad13f 100644
--- a/spec/requests/categories_controller_spec.rb
+++ b/spec/requests/categories_controller_spec.rb
@@ -44,4 +44,9 @@
         }
     expect(Category.can_vote?(category.id)).to eq(false)
   end
+
+  it "works fine when `custom_fields` isn't passed " do
+    put "/categories/#{category.id}.json", params: { hello: "world" }
+    expect(response.status).to eq(200)
+  end
 end