diff --git a/ChangeLog b/ChangeLog
index 4f5f4b159e..c7853b63b8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Aug 27 05:11:51 2010  Tanaka Akira  <akr@fsij.org>
+
+	* ext/pathname/pathname.c (path_sysopen): Pathname#sysopen translated
+	  from pathname.rb.
+
 Thu Aug 26 22:53:56 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* array.c (rb_ary_shuffle): rdoc fix.  argument name was missing.
diff --git a/ext/pathname/lib/pathname.rb b/ext/pathname/lib/pathname.rb
index b4c701a084..c9bf0c5fb8 100644
--- a/ext/pathname/lib/pathname.rb
+++ b/ext/pathname/lib/pathname.rb
@@ -483,12 +483,6 @@ class Pathname
   end
 end
 
-class Pathname    # * IO *
-
-  # See <tt>IO.sysopen</tt>.
-  def sysopen(*args) IO.sysopen(@path, *args) end
-end
-
 
 class Pathname    # * FileTest *
 
diff --git a/ext/pathname/pathname.c b/ext/pathname/pathname.c
index 2918ef0ecb..f5ba6dc1ae 100644
--- a/ext/pathname/pathname.c
+++ b/ext/pathname/pathname.c
@@ -320,6 +320,24 @@ path_readlines(int argc, VALUE *argv, VALUE self)
     return rb_funcall2(rb_cIO, rb_intern("readlines"), 1+n, args);
 }
 
+/*
+ * call-seq:
+ *   pathname.sysopen([mode, [perm]])  -> fixnum
+ *        
+ * See <tt>IO.sysopen</tt>.
+ *
+ */
+static VALUE
+path_sysopen(int argc, VALUE *argv, VALUE self)
+{
+    VALUE args[3];
+    int n;
+
+    args[0] = get_strpath(self);
+    n = rb_scan_args(argc, argv, "02", &args[1], &args[2]);
+    return rb_funcall2(rb_cIO, rb_intern("sysopen"), 1+n, args);
+}
+
 /*
  * See <tt>File.atime</tt>.  Returns last access time.
  */
@@ -783,6 +801,7 @@ Init_pathname()
     rb_define_method(rb_cPathname, "read", path_read, -1);
     rb_define_method(rb_cPathname, "binread", path_binread, -1);
     rb_define_method(rb_cPathname, "readlines", path_readlines, -1);
+    rb_define_method(rb_cPathname, "sysopen", path_sysopen, -1);
     rb_define_method(rb_cPathname, "atime", path_atime, 0);
     rb_define_method(rb_cPathname, "ctime", path_ctime, 0);
     rb_define_method(rb_cPathname, "mtime", path_mtime, 0);