diff --git a/spec/rubocop/formatter/checkstyle_formatter_spec.rb b/spec/rubocop/formatter/checkstyle_formatter_spec.rb
index 42afdf5..9d3c5c8 100644
--- a/spec/rubocop/formatter/checkstyle_formatter_spec.rb
+++ b/spec/rubocop/formatter/checkstyle_formatter_spec.rb
@@ -13,7 +13,7 @@ module Formatter
           c.send(:begin_investigation, RuboCop::ProcessedSource.new(file, 2.7, 'sample.rb'))
           source_buffer = Parser::Source::Buffer.new('sample.rb', 1).tap { |b| b.source = '' }
           severities.each_with_index do |severity, index|
-            c.add_offense(nil, location: Parser::Source::Range.new(source_buffer, 0, index), message: severity.to_s)
+            c.add_offense(Parser::Source::Range.new(source_buffer, 0, index), message: severity.to_s)
           end
         end
       end