diff --git a/ChangeLog b/ChangeLog
index d51ea17082..7eb313aade 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Feb 14 10:45:31 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* test/ruby/test_process.rb (test_setsid): Added a workaround for
+	  MacOS X. Patch by nagachika. [Bug #7826] [ruby-core:52126]
+
 Fri Feb 15 00:15:31 2013  Tanaka Akira  <akr@fsij.org>
 
 	* ext/socket/sockport.h (VALIDATE_SOCKLEN): new macro to validate
diff --git a/test/ruby/test_process.rb b/test/ruby/test_process.rb
index 96335c273c..6616955502 100644
--- a/test/ruby/test_process.rb
+++ b/test/ruby/test_process.rb
@@ -1583,6 +1583,9 @@ class TestProcess < Test::Unit::TestCase
 	newsid = Process.setsid
 	Marshal.dump(newsid, STDOUT)
 	STDOUT.flush
+	# getsid() on MacOS X return ESRCH when target process is zombie
+	# even if it is valid process id.
+	sleep
 EOS
       begin
         # test Process.getsid() w/o arg