diff --git a/app/models/filter/params.rb b/app/models/filter/params.rb
index 0166b17e7..c6f0df13e 100644
--- a/app/models/filter/params.rb
+++ b/app/models/filter/params.rb
@@ -23,7 +23,7 @@ module Filter::Params
     end
 
     def normalize_params(params)
-      params.to_h.compact_blank.reject(&method(:default_value?)).sort_by { |k, _| k.to_s }
+      params.to_h.compact_blank.reject(&method(:default_value?)).sort_by { |name, _| name.to_s }
     end
   end