diff --git a/ChangeLog b/ChangeLog
index a36360f51a..816f468b9f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Feb 21 23:10:12 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/mkmf.rb (RbConfig): expand RUBY_SO_NAME for extensions
+	  backward compatibility.  [ruby-core:59426] [Bug #9329]
+
 Fri Feb 21 23:07:56 2014  Akio Tajima <artonx@yahoo.co.jp>
 
 	* win32/Makefile.sub: remove HAVE_FSEEKO because fseeko removed from win32/win32.c
diff --git a/lib/mkmf.rb b/lib/mkmf.rb
index c4e2e5a900..2d44b123d2 100644
--- a/lib/mkmf.rb
+++ b/lib/mkmf.rb
@@ -2508,6 +2508,8 @@ MESSAGE
   $configure_args["--topdir"] ||= $curdir
   $ruby = arg_config("--ruby", File.join(RbConfig::CONFIG["bindir"], CONFIG["ruby_install_name"]))
 
+  RbConfig.expand(CONFIG["RUBY_SO_NAME"])
+
   # :startdoc:
 
   split = Shellwords.method(:shellwords).to_proc
diff --git a/version.h b/version.h
index 9d7241d82c..f02c538597 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.1.1"
 #define RUBY_RELEASE_DATE "2014-02-21"
-#define RUBY_PATCHLEVEL 45
+#define RUBY_PATCHLEVEL 46
 
 #define RUBY_RELEASE_YEAR 2014
 #define RUBY_RELEASE_MONTH 2