diff --git a/ChangeLog b/ChangeLog
index 8a9ea979ea..abfa77c6ac 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Sep 20 11:25:49 2010  Tanaka Akira  <akr@fsij.org>
+
+	* ext/pathname/pathname.c (Init_pathname): Pathname#=~ undefinition
+	  translated from pathname.rb.
+
 Mon Sep 20 02:34:11 2010  Kenta Murata  <mrkn@mrkn.jp>
 
 	* ext/bigdecimal/bigdecimal.c (check_rounding_mode, BigDecimal_mode):
diff --git a/ext/pathname/lib/pathname.rb b/ext/pathname/lib/pathname.rb
index 0c1351dc1e..f6e06f2092 100644
--- a/ext/pathname/lib/pathname.rb
+++ b/ext/pathname/lib/pathname.rb
@@ -526,10 +526,6 @@ class Pathname    # * FileUtils *
 end
 
 
-class Pathname
-  undef =~
-end
-
 module Kernel
   # create a pathname object.
   #
diff --git a/ext/pathname/pathname.c b/ext/pathname/pathname.c
index f5a0182bf0..b3fe3af9ca 100644
--- a/ext/pathname/pathname.c
+++ b/ext/pathname/pathname.c
@@ -1224,4 +1224,5 @@ Init_pathname()
     rb_define_method(rb_cPathname, "each_entry", path_each_entry, 0);
     rb_define_method(rb_cPathname, "unlink", path_unlink, 0);
     rb_define_method(rb_cPathname, "delete", path_unlink, 0);
+    rb_undef_method(rb_cPathname, "=~");
 }