diff --git a/app/models/tag.rb b/app/models/tag.rb
index e6cec3c50..0bf82bb48 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -158,6 +158,8 @@ class Tag < ApplicationRecord
       end
 
       def category_for(tag_name, options = {})
+        return Tag.categories.general if tag_name.blank?
+
         if options[:disable_caching]
           select_category_for(tag_name)
         else