diff --git a/ChangeLog b/ChangeLog
index e1bf3bc26a..2a4b3c86e1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Dec 11 19:16:30 2008  Tanaka Akira  <akr@fsij.org>
+
+	* lib/pathname.rb (Pathname#=~): undefed.  at asakusa.rb.
+	  [ruby-core:19690]
+
 Thu Dec 11 13:09:01 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* re.c (reg_enc_error): raise EncodingCompatibilityError for
diff --git a/lib/pathname.rb b/lib/pathname.rb
index 1bc0063bb0..86f0f54800 100644
--- a/lib/pathname.rb
+++ b/lib/pathname.rb
@@ -1063,6 +1063,10 @@ class Pathname    # * mixed *
   end
 end
 
+class Pathname
+  undef =~
+end
+
 module Kernel
   # create a pathname object.
   #