--- configure.in.lib64	2009-10-28 15:15:32.000000000 +0100
+++ configure.in	2010-01-17 07:09:01.000000000 +0100
@@ -2002,7 +2002,7 @@
     rubyw_install_name="$RUBYW_INSTALL_NAME"
     ;;
 esac
-RUBY_LIB_PREFIX=`eval echo \\"${libdir}/${RUBY_INSTALL_NAME}\\"`
+RUBY_LIB_PREFIX=`eval echo \\"${prefix}/lib/${RUBY_INSTALL_NAME}\\"`
 
 AC_ARG_WITH(ruby-version,
 	    [  --with-ruby-version=STR ruby version string for version specific directories [[full]] (full|minor|STR)],
--- ext/tk/extconf.rb.lib64	2008-10-20 01:22:10.000000000 +0200
+++ ext/tk/extconf.rb	2010-01-17 07:08:05.000000000 +0100
@@ -45,6 +45,11 @@
   have_library("m", "log") 
 end
 
+$lib = "lib"
+if RUBY_PLATFORM =~ /(x86_64|powerpc64)-linux/
+   $lib = "lib64"
+end
+
 tk_idir,  tk_ldir  = dir_config("tk")
 tcl_idir, tcl_ldir = dir_config("tcl")
 x11_idir, x11_ldir = dir_config("X11")
@@ -112,7 +117,7 @@
 end
 
 def find_tcl(tcllib, stubs, version, *opt_paths)
-  default_paths = ["/usr/local/lib", "/usr/pkg/lib", "/usr/lib"]
+  default_paths = ["/usr/local/#{$lib}", "/usr/pkg/lib", "/usr/#{$lib}"]
   default_paths << "/Tcl/lib"  # default for ActiveTcl
 
   if (paths = opt_paths.compact).empty?
@@ -155,7 +160,7 @@
 end
 
 def find_tk(tklib, stubs, version, *opt_paths)
-  default_paths = ["/usr/local/lib", "/usr/pkg/lib", "/usr/lib"]
+  default_paths = ["/usr/local/#{$lib}", "/usr/pkg/lib", "/usr/#{$lib}"]
   default_paths << "/Tcl/lib"  # default for ActiveTcl
 
   if (paths = opt_paths.compact).empty?
@@ -228,7 +233,7 @@
 
 def find_X11(*opt_paths)
   default_paths = 
-    [ "/usr/X11/lib", "/usr/lib/X11", "/usr/X11R6/lib", "/usr/openwin/lib" ]
+    [ "/usr/X11/#{$lib}", "/usr/#{$lib}/X11", "/usr/X11R6/#{$lib}", "/usr/openwin/lib" ]
   paths = opt_paths.compact.concat(default_paths)
   st = find_library("X11", "XOpenDisplay", *paths)
   unless st
--- mkconfig.rb.lib64	2008-12-12 15:54:37.000000000 +0100
+++ mkconfig.rb	2010-01-17 07:11:23.000000000 +0100
@@ -140,8 +140,8 @@
 print(*v_fast)
 print(*v_others)
 print <<EOS
-  CONFIG["rubylibdir"] = "$(libdir)/$(ruby_install_name)/$(ruby_version)"
-  CONFIG["archdir"] = "$(rubylibdir)/$(arch)"
+  CONFIG["rubylibdir"] = "$(prefix)/lib/$(ruby_install_name)/$(ruby_version)"
+  CONFIG["archdir"] = "$(prefix)/lib/$(ruby_install_name)/$(ruby_version)/$(arch)"
   CONFIG["sitelibdir"] = "$(sitedir)/$(ruby_version)"
   CONFIG["sitearchdir"] = "$(sitelibdir)/$(sitearch)"
   CONFIG["vendorlibdir"] = "$(vendordir)/$(ruby_version)"