diff --git a/.rdoc_options b/.rdoc_options
index 79a8fce..24fe2d7 100644
--- a/.rdoc_options
+++ b/.rdoc_options
@@ -2,3 +2,4 @@
 page_dir: doc
 main_page: README.md
 title: Documentation for OptionParser
+op_dir: rdoc
diff --git a/optparse.gemspec b/optparse.gemspec
index 1aa54aa..126f71b 100644
--- a/optparse.gemspec
+++ b/optparse.gemspec
@@ -24,7 +24,6 @@ Gem::Specification.new do |spec|
 
   spec.files         = Dir["{doc,lib,misc}/**/{*,.document}"] +
                        %w[README.md ChangeLog COPYING .document .rdoc_options]
-  spec.rdoc_options  = ["--main=README.md", "--op=rdoc", "--page-dir=doc"]
   spec.bindir        = "exe"
   spec.executables   = []
   spec.require_paths = ["lib"]
diff --git a/rakelib/changelogs.rake b/rakelib/changelogs.rake
index 5e00c98..9be2e8a 100644
--- a/rakelib/changelogs.rake
+++ b/rakelib/changelogs.rake
@@ -23,7 +23,7 @@ end
 tags = IO.popen(%w[git tag -l v[0-9]*]).grep(/v(.*)/) {$1}
 unless tags.empty?
   tags.sort_by! {|tag| tag.scan(/\d+/).map(&:to_i)}
-  tags.pop if IO.popen(%W[git log --format=%H v#{tags.last}..HEAD --], &:read).empty?
+  tags.pop if IO.popen(%W[git rev-list --right-only --count v#{tags.last}..HEAD --], &:read).to_i == 0
   tags.inject(nil) do |prev, tag|
     task("logs/ChangeLog-#{tag}") {|t| changelog[t.name, tag, prev]}
     tag