diff --git a/.document b/.document
new file mode 100644
index 0000000..6eeabcd
--- /dev/null
+++ b/.document
@@ -0,0 +1,2 @@
+readme.rdoc
+lib/**/*.rb
\ No newline at end of file
diff --git a/asin.gemspec b/asin.gemspec
index 9c00215..3b4eee9 100644
--- a/asin.gemspec
+++ b/asin.gemspec
@@ -12,7 +12,7 @@ spec = Gem::Specification.new do |s|
 
   s.has_rdoc = true
   s.rdoc_options = ['-a', '--inline-source', '--charset=UTF-8']
-  s.extra_rdoc_files = ['README']
+  s.extra_rdoc_files = ['readme.rdoc']
   s.files = Dir.glob('lib/*.rb')
   s.test_files = Dir.glob('test/test_*.rb')
   
diff --git a/rakefile.rb b/rakefile.rb
index 314a437..5d77da4 100644
--- a/rakefile.rb
+++ b/rakefile.rb
@@ -10,7 +10,7 @@
 
 
 Rake::RDocTask.new(:rdoc_dev) do |rd|
-  rd.rdoc_files.include("lib/**/*.rb", "README")
+  rd.rdoc_files.include("lib/**/*.rb", "readme.rdoc")
   rd.options + ['-a', '--inline-source', '--charset=UTF-8']
 end
 
diff --git a/README b/readme.rdoc
similarity index 100%
rename from README
rename to readme.rdoc