diff --git a/ChangeLog b/ChangeLog
index b2e73d65a9..7622b7957e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jul 30 23:01:47 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* lib/rubygems/platform.rb (Gem::Platform#initialize): Support pattern
+	  like x86_64-netbsd6.99.7.
+
 Mon Jul 30 21:00:53 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* variable.c (find_class_path): no retry when preferred is given.
diff --git a/lib/rubygems/platform.rb b/lib/rubygems/platform.rb
index 682714a5de..f67e4022b6 100644
--- a/lib/rubygems/platform.rb
+++ b/lib/rubygems/platform.rb
@@ -81,7 +81,7 @@ class Gem::Platform
                         os, version = $1, $3
                         @cpu = 'x86' if @cpu.nil? and os =~ /32$/
                         [os, version]
-                      when /netbsdelf/ then            [ 'netbsdelf', nil ]
+                      when /(netbsd[a-z]*)(\d+)/ then [ $1,          $2  ]
                       when /openbsd(\d+\.\d+)/ then    [ 'openbsd',   $1  ]
                       when /solaris(\d+\.\d+)/ then    [ 'solaris',   $1  ]
                       # test
diff --git a/test/rubygems/test_gem_platform.rb b/test/rubygems/test_gem_platform.rb
index 0350d5f028..b6ddc0eca4 100644
--- a/test/rubygems/test_gem_platform.rb
+++ b/test/rubygems/test_gem_platform.rb
@@ -67,7 +67,8 @@ class TestGemPlatform < Gem::TestCase
       'x86-mswin32'            => ['x86',       'mswin32',   nil],
       'x86-mswin32_60'         => ['x86',       'mswin32',   '60'],
       'x86-mswin32-60'         => ['x86',       'mswin32',   '60'],
-      'i386-netbsdelf'         => ['x86',       'netbsdelf', nil],
+      'i386-netbsdelf5.1.'     => ['x86',       'netbsdelf', '5'],
+      'x86_64-netbsd6.99.7'    => ['x86_64',    'netbsd',    '6'],
       'i386-openbsd4.0'        => ['x86',       'openbsd',   '4.0'],
       'i386-solaris2.10'       => ['x86',       'solaris',   '2.10'],
       'i386-solaris2.8'        => ['x86',       'solaris',   '2.8'],