diff --git a/ChangeLog b/ChangeLog
index 3eb519d086..6cc7719792 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Oct  7 17:54:28 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/test/unit/assertions.rb (assert_send, assert_not_send):
+	  parenthesize non-empty arguments.
+
 Fri Oct  7 06:35:50 2011  Eric Hodel  <drbrain@segment7.net>
 
 	* array.c:  Use + for arguments described in documentation to allow
diff --git a/lib/test/unit/assertions.rb b/lib/test/unit/assertions.rb
index a56998ff17..157cbac743 100644
--- a/lib/test/unit/assertions.rb
+++ b/lib/test/unit/assertions.rb
@@ -272,7 +272,7 @@ EOT
           if args.empty?
             argsstr = ""
           else
-            (argsstr = mu_pp(args)).sub!(/\A\[(.*)\]\z/m, '\1')
+            (argsstr = mu_pp(args)).sub!(/\A\[(.*)\]\z/m, '(\1)')
           end
           "Expected #{mu_pp(recv)}.#{msg}#{argsstr} to return true"
         }
@@ -298,7 +298,7 @@ EOT
           if args.empty?
             argsstr = ""
           else
-            (argsstr = mu_pp(args)).sub!(/\A\[(.*)\]\z/m, '\1')
+            (argsstr = mu_pp(args)).sub!(/\A\[(.*)\]\z/m, '(\1)')
           end
           "Expected #{mu_pp(recv)}.#{msg}#{argsstr} to return false"
         }