diff --git a/ChangeLog b/ChangeLog
index 4d869bc735..54c2b473f7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Feb  8 08:50:42 2013  Aaron Patterson <aaron@tenderlovemaking.com>
+
+	* ext/psych/lib/psych/visitors/yaml_tree.rb: change output reference
+	  ids to be sequential numbers.
+
 Fri Feb  8 07:47:56 2013  Eric Hodel  <drbrain@segment7.net>
 
 	* lib/rubygems/package/old.rb:  Disallow installation of old-format
diff --git a/ext/psych/lib/psych/visitors/yaml_tree.rb b/ext/psych/lib/psych/visitors/yaml_tree.rb
index ce40a17eb3..53cbad3e10 100644
--- a/ext/psych/lib/psych/visitors/yaml_tree.rb
+++ b/ext/psych/lib/psych/visitors/yaml_tree.rb
@@ -8,6 +8,30 @@ module Psych
     #   builder.tree # => #<Psych::Nodes::Stream .. }
     #
     class YAMLTree < Psych::Visitors::Visitor
+      class Registrar # :nodoc:
+        def initialize
+          @obj_to_id   = {}
+          @obj_to_node = {}
+          @counter     = 0
+        end
+
+        def register target, node
+          @obj_to_node[target.object_id] = node
+        end
+
+        def key? target
+          @obj_to_node.key? target.object_id
+        end
+
+        def id_for target
+          @obj_to_id[target.object_id] ||= (@counter += 1)
+        end
+
+        def node_for target
+          @obj_to_node[target.object_id]
+        end
+      end
+
       attr_reader :started, :finished
       alias :finished? :finished
       alias :started? :started
@@ -17,7 +41,7 @@ module Psych
         @started  = false
         @finished = false
         @emitter  = emitter
-        @st       = {}
+        @st       = Registrar.new
         @ss       = ss
         @options  = options
         @coders   = []
@@ -72,9 +96,9 @@ module Psych
 
       def accept target
         # return any aliases we find
-        if @st.key? target.object_id
-          oid         = target.object_id
-          node        = @st[oid]
+        if @st.key? target
+          oid         = @st.id_for target
+          node        = @st.node_for target
           anchor      = oid.to_s
           node.anchor = anchor
           return @emitter.alias anchor
@@ -410,7 +434,7 @@ module Psych
       end
 
       def register target, yaml_obj
-        @st[target.object_id] = yaml_obj
+        @st.register target, yaml_obj
         yaml_obj
       end