diff --git a/ChangeLog b/ChangeLog
index 937459e667..ca4bd6f6cd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Jul  5 23:44:06 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* instruby.rb: expand source library path.
+
 Tue Jul  5 23:27:14 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* array.c (sort_2): get rid of yet another bcc's bug.
diff --git a/instruby.rb b/instruby.rb
index f1225a4707..be011d46ab 100644
--- a/instruby.rb
+++ b/instruby.rb
@@ -4,7 +4,7 @@ load "./rbconfig.rb"
 include Config
 
 srcdir = File.dirname(__FILE__)
-$:.unshift File.join(srcdir, "lib")
+$:.unshift File.expand_path("lib", srcdir)
 require 'fileutils'
 require 'shellwords'
 require 'optparse'
@@ -82,7 +82,7 @@ def makedirs(dirs)
 end
 
 def with_destdir(dir)
-  return dir if $destdir.empty?
+  return dir if !$destdir or $destdir.empty?
   dir = dir.sub(/\A\w:/, '') if File::PATH_SEPARATOR == ';'
   $destdir + dir
 end