diff --git a/ChangeLog b/ChangeLog
index f00c1d8bfb..adb8309648 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -15,7 +15,7 @@ Sun Sep 21 07:43:16 2008  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* lib/mathn.rb: ditto.
 
-	* lib/complex.rb: ditto.
+	* lib/complex.rb: ditto. and provides some obsolate methods.
 
 Sun Sep 21 02:48:45 2008  NARUSE, Yui  <naruse@ruby-lang.org>
 
diff --git a/lib/complex.rb b/lib/complex.rb
index c03ee63c3e..301879143f 100644
--- a/lib/complex.rb
+++ b/lib/complex.rb
@@ -16,3 +16,9 @@ class Complex
   alias image imag
 
 end
+
+class Numeric
+
+  def im() Complex(0, self) end
+
+end