Maybe something like this, but I'm not sure:

RCS file: /src/ruby/lib/yaml/rubytypes.rb,v
retrieving revision 1.16.2.9
diff -u -r1.16.2.9 rubytypes.rb
--- lib/yaml/rubytypes.rb       20 Sep 2005 06:46:45 -0000      1.16.2.9
+++ lib/yaml/rubytypes.rb       2 Oct 2005 07:06:49 -0000
@@ -372,6 +372,10 @@
     yaml_as "tag:yaml.org,2002:int"
 end

+class Bignum
+    yaml_as "tag:yaml.org,2002:int"
+end
+
 class Float
     yaml_as "tag:yaml.org,2002:float"
 end

Kent.

On Sat, 2005-10-01 at 20:13 +0900, akira yamada / やまだあきら wrote:
> I received a report from a Debian user:
> <URL:http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=331050>
> 
> In Ruby 1.8.2:
> 
>   $ ruby -v
>   ruby 1.8.2 (2005-04-11) [i386-linux]
>   $ ruby -ryaml -e 'puts YAML.dump(1234567890)'
>   --- 1234567890
>   $ ruby -ryaml -e 'puts YAML.dump(1234567890)' | ruby -ryaml -e 'p YAML.load(ARGF.read)'
>   1234567890
> 
> In Ruby 1.8.3 (and trunk):
> 
>   $ ruby -v
>   ruby 1.8.3 (2005-09-21) [i486-linux]
>   $ ruby -ryaml -e 'puts YAML.dump(1234567890)'
>   !ruby/object:Bignum 1234567890
>   $ ruby -ryaml -e 'puts YAML.dump(1234567890)' | ruby -ryaml -e 'p YAML.load(ARGF.read)'
>   /usr/lib/ruby/1.8/yaml.rb:133:in `transfer': allocator undefined for Bignum (TypeError)
>           from /usr/lib/ruby/1.8/yaml.rb:133:in `load'
>           from -e:1
> 
> It is a bug of Ruby 1.8.3.  I think that YAML should be able to load
> "!ruby/object:Bignum 1234567890".
> 
> Thank you.