diff --git a/railties/lib/rails/tasks/documentation.rake b/railties/lib/rails/tasks/documentation.rake
index ca8875ad9b..2072a2b947 100644
--- a/railties/lib/rails/tasks/documentation.rake
+++ b/railties/lib/rails/tasks/documentation.rake
@@ -66,31 +66,31 @@ namespace :doc do
     rdoc.rdoc_files.include('README')
 
     gem_path('actionmailer') do |actionmailer|
-      %w(README.rdoc CHANGELOG MIT-LICENSE lib/action_mailer/base.rb).each do |file|
+      %w(README.rdoc CHANGELOG.md MIT-LICENSE lib/action_mailer/base.rb).each do |file|
         rdoc.rdoc_files.include("#{actionmailer}/#{file}")
       end
     end
 
     gem_path('actionpack') do |actionpack|
-      %w(README.rdoc CHANGELOG MIT-LICENSE lib/action_controller/**/*.rb lib/action_view/**/*.rb).each do |file|
+      %w(README.rdoc CHANGELOG.md MIT-LICENSE lib/action_controller/**/*.rb lib/action_view/**/*.rb).each do |file|
         rdoc.rdoc_files.include("#{actionpack}/#{file}")
       end
     end
 
     gem_path('activemodel') do |activemodel|
-      %w(README.rdoc CHANGELOG MIT-LICENSE lib/active_model/**/*.rb).each do |file|
+      %w(README.rdoc CHANGELOG.md MIT-LICENSE lib/active_model/**/*.rb).each do |file|
         rdoc.rdoc_files.include("#{activemodel}/#{file}")
       end
     end
 
     gem_path('activerecord') do |activerecord|
-      %w(README.rdoc CHANGELOG lib/active_record/**/*.rb).each do |file|
+      %w(README.rdoc CHANGELOG.md lib/active_record/**/*.rb).each do |file|
         rdoc.rdoc_files.include("#{activerecord}/#{file}")
       end
     end
 
     gem_path('activeresource') do |activeresource|
-      %w(README.rdoc CHANGELOG lib/active_resource.rb lib/active_resource/*).each do |file|
+      %w(README.rdoc CHANGELOG.md lib/active_resource.rb lib/active_resource/*).each do |file|
         rdoc.rdoc_files.include("#{activeresource}/#{file}")
       end
     end
diff --git a/tasks/release.rb b/tasks/release.rb
index 2422efa786..780543aa78 100644
--- a/tasks/release.rb
+++ b/tasks/release.rb
@@ -66,7 +66,7 @@ namespace :changelog do
     FRAMEWORKS.each do |fw|
       require 'date'
       replace = '\1(' + Date.today.strftime('%B %d, %Y') + ')'
-      fname = File.join fw, 'CHANGELOG'
+      fname = File.join fw, 'CHANGELOG.md'
 
       contents = File.read(fname).sub(/^([^(]*)\(unreleased\)/, replace)
       File.open(fname, 'wb') { |f| f.write contents }
@@ -76,7 +76,7 @@ namespace :changelog do
   task :release_summary do
     FRAMEWORKS.each do |fw|
       puts "## #{fw}"
-      fname    = File.join fw, 'CHANGELOG'
+      fname    = File.join fw, 'CHANGELOG.md'
       contents = File.readlines fname
       contents.shift
       changes = []