diff --git a/ChangeLog b/ChangeLog
index b14a0e1abc..3fb77cf2b1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Apr  8 11:00:14 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* lib/complex.rb: remove Math first before overwriting by CMath.
+
 Tue Apr  8 10:34:10 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* load.c (rb_require_safe): should check fname path after $SAFE is
diff --git a/lib/complex.rb b/lib/complex.rb
index c5fbb36a4a..0e88dd5f4f 100644
--- a/lib/complex.rb
+++ b/lib/complex.rb
@@ -1,3 +1,4 @@
 require 'cmath'
 
+Object.instance_eval{remove_const :Math}
 Math = CMath