diff --git a/ChangeLog b/ChangeLog
index 910b333cd9..40b4a1e0e7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu May 27 21:37:50 2004  Tanaka Akira  <akr@m17n.org>
+
+	* lib/pathname.rb (Pathname#initialize): fix pathname initialization
+	  by pathname.
+
 Thu May 27 20:02:09  Hirokazu Yamamoto  <ocean@m2.ccsnet.ne.jp>
 
 	* io.c (rb_io_fwrite): check all case errno != 0 [ruby-dev:23648]
diff --git a/lib/pathname.rb b/lib/pathname.rb
index c4d0ea586a..bd8afb081d 100644
--- a/lib/pathname.rb
+++ b/lib/pathname.rb
@@ -187,7 +187,8 @@ class Pathname
   # If +path+ contains a NUL character (<tt>\0</tt>), an ArgumentError is raised.
   #
   def initialize(path)
-    @path = path.to_str.dup
+    path = path.to_path if path.respond_to? :to_path
+    @path = path.dup
 
     if /\0/ =~ @path
       raise ArgumentError, "pathname contains \\0: #{@path.inspect}"
@@ -890,6 +891,13 @@ if $0 == __FILE__
   require 'test/unit'
 
   class PathnameTest < Test::Unit::TestCase # :nodoc:
+    def test_initialize
+      p1 = Pathname.new('a')
+      assert_equal('a', p1.to_s)
+      p2 = Pathname.new(p1)
+      assert_equal(p1, p2)
+    end
+
     class AnotherStringLike # :nodoc:
       def initialize(s) @s = s end
       def to_str() @s end