diff --git a/ChangeLog b/ChangeLog
index acf9a160ed..cb03e2df6c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Dec 21 12:15:32 2015  Kimura Wataru  <kimuraw@i.nifty.jp>
+
+	* test/ruby/test_io.rb: handled rlimit value same as r52277
+	  [Bug #11852][ruby-dev:49446]
+
 Mon Dec 21 10:21:22 2015  Ilya Vassilevsky <vassilevsky@gmail.com>
 
 	* lib/net/http.rb (open_timeout): update default value in RDoc
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 723858a0b8..766804eb2e 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1094,7 +1094,10 @@ class TestIO < Test::Unit::TestCase
     args = ['-e', '$>.write($<.read)'] if args.empty?
     ruby = EnvUtil.rubybin
     opts = {}
-    opts[:rlimit_nproc] = 1024 if defined?(Process::RLIMIT_NPROC)
+    if defined?(Process::RLIMIT_NPROC)
+      lim = Process.getrlimit(Process::RLIMIT_NPROC)[1]
+      opts[:rlimit_nproc] = [lim, 1024].min
+    end
     f = IO.popen([ruby] + args, 'r+', opts)
     pid = f.pid
     yield(f)