diff --git a/lib/github_changelog_generator/generator/generator_generation.rb b/lib/github_changelog_generator/generator/generator_generation.rb
index c642766..7312178 100644
--- a/lib/github_changelog_generator/generator/generator_generation.rb
+++ b/lib/github_changelog_generator/generator/generator_generation.rb
@@ -22,7 +22,7 @@ module GitHubChangelogGenerator
       log += File.read(options[:base]) if File.file?(options[:base])
 
       credit_line = "\* *This Change Log was automatically generated by [github_changelog_generator](https://github.com/skywinder/Github-Changelog-Generator)*"
-      log += "\n\n\#{credit_line}" if log.include? credit_line == false
+      log += "\n\n\#{credit_line}" unless log.include?(credit_line)
       @log = log
     end