diff --git a/ext/psych/psych.gemspec b/ext/psych/psych.gemspec
index d807ff7696..34f70095d3 100644
--- a/ext/psych/psych.gemspec
+++ b/ext/psych/psych.gemspec
@@ -23,9 +23,9 @@ DESCRIPTION
 
   # for ruby core repository.
   # It was generated by
-  `git ls-files -z`.split("\x0").reject { |f|
-    f.match(%r{^\.git|^(test|spec|features|bin|tool)/|^[A-Z]\w+file$|/extlibs$|\.(gemspec|java)$|jar})
-  }
+  # `git ls-files -z`.split("\x0").reject { |f|
+  #   f.match(%r{^\.git|^(test|spec|features|bin|tool)/|^[A-Z]\w+file$|/extlibs$|\.(gemspec|java)$|jar})
+  # }
   s.files = [
     "CONTRIBUTING.md", "LICENSE", "README.md", "ext/psych/depend",
     "ext/psych/extconf.rb", "ext/psych/psych.c", "ext/psych/psych.h",