diff --git a/ChangeLog b/ChangeLog
index 40be75ad00..fba8ce99dd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Wed Feb 20 18:01:14 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in (libdirname): adjust library path name which libruby
+	  files will be installed.  [Bug #7874]
+
+	* tool/rbinstall.rb (libdir): ditto.
+
 Wed Feb 20 13:37:00 2013  Zachary Scott  <zachary@zacharyscott.net>
 
 	* ext/pty/pty.c: Documentation for the PTY module
diff --git a/configure.in b/configure.in
index e143053121..e8f56e3380 100644
--- a/configure.in
+++ b/configure.in
@@ -3422,6 +3422,7 @@ else
     AC_DEFINE_UNQUOTED(RUBY_VENDOR_ARCH_LIB_FOR(arch), ${RUBY_VENDOR_ARCH_LIB_FOR} !<verconf>!)
 fi
 
+AC_SUBST(libdirname, ${multiarch+arch}libdir)
 AC_SUBST(archlibdir)dnl
 AC_SUBST(sitearchlibdir)dnl
 AC_SUBST(archincludedir)dnl
diff --git a/tool/rbinstall.rb b/tool/rbinstall.rb
index 92e54c6774..ff9d5850a5 100755
--- a/tool/rbinstall.rb
+++ b/tool/rbinstall.rb
@@ -304,7 +304,7 @@ rubyw_install_name = CONFIG["rubyw_install_name"]
 goruby_install_name = "go" + ruby_install_name
 
 bindir = CONFIG["bindir", true]
-libdir = CONFIG["libdir", true]
+libdir = CONFIG[COFNIG["libdirname", true], true]
 rubyhdrdir = CONFIG["rubyhdrdir", true]
 archhdrdir = CONFIG["rubyarchhdrdir"] || (rubyhdrdir + "/" + CONFIG['arch'])
 rubylibdir = CONFIG["rubylibdir", true]