diff --git a/ChangeLog b/ChangeLog
index 6b491d7290..1ea01e3e08 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Feb  7 22:56:16 2011  CHIKANAGA Tomoyuki  <nagachika00@gmail.com>
+
+	* lib/benchmark.rb (Benchmark#bmbm): use ensure clause instead of
+	  Object#tap to restore STDOUT.sync.
+
 Mon Feb  7 22:34:20 2011  Tanaka Akira  <akr@fsij.org>
 
 	* lib/net/http.rb (Net::HTTP#connect): support SNI (Server Name
diff --git a/lib/benchmark.rb b/lib/benchmark.rb
index 052b9add3b..ac17ba436d 100644
--- a/lib/benchmark.rb
+++ b/lib/benchmark.rb
@@ -266,9 +266,9 @@ module Benchmark
       GC.start
       print label.ljust(width)
       Benchmark.measure(&item).tap { |res| print res.format }
-    }.tap {
-      STDOUT.sync = sync
     }
+  ensure
+    STDOUT.sync = sync unless sync.nil?
   end
 
   #