diff --git a/devel/migrate-vmodl.rb b/devel/migrate-vmodl.rb
new file mode 100644
index 00000000..3df56c01
--- /dev/null
+++ b/devel/migrate-vmodl.rb
@@ -0,0 +1,20 @@
+#!/usr/bin/env ruby
+# Migrate vmodl.db from marchal db to yaml format
+require 'yaml'
+
+input_vmodl_filename = ARGV[0] or abort 'input vmodl filename required'
+output_vmodl_filename = ARGV[1] or abort 'output vmodl filename required'
+
+input_vmodl = case File.extname(input_vmodl_filename)
+              when '.yml', '.yaml'
+                File.open(input_vmodl_filename, 'r') { |io| YAML.load_file io }
+              when '.db'
+                File.open(input_vmodl_filename, 'r') { |io| Marshal.load io }
+              end
+
+case File.extname(output_vmodl_filename)
+when '.yml', '.yaml'
+  File.open(output_vmodl_filename, 'w') { |io| YAML.dump(input_vmodl, io) }
+when '.db'
+  File.open(output_vmodl_filename, 'w') { |io| Marshal.dump(input_vmodl, io) }
+end
diff --git a/lib/rbvmomi/connection.rb b/lib/rbvmomi/connection.rb
index a9b4e915..cad224b4 100644
--- a/lib/rbvmomi/connection.rb
+++ b/lib/rbvmomi/connection.rb
@@ -261,6 +261,10 @@ def self.method_missing sym, *a
     end
   end
 
+  def self.vmodl_filename
+    ENV['VMODL'] || Dir[File.join(File.dirname(__FILE__), "../../vmodl.*")].first
+  end
+
   def self.load_vmodl fn
     @loader = RbVmomi::TypeLoader.new fn, extension_dirs, self
     nil
diff --git a/lib/rbvmomi/pbm.rb b/lib/rbvmomi/pbm.rb
index b8a796b3..5205e466 100644
--- a/lib/rbvmomi/pbm.rb
+++ b/lib/rbvmomi/pbm.rb
@@ -60,7 +60,7 @@ def pretty_print pp
   end
 
   add_extension_dir File.join(File.dirname(__FILE__), "pbm")
-  load_vmodl(ENV['VMODL'] || File.join(File.dirname(__FILE__), "../../vmodl.db"))
+  load_vmodl(vmodl_filename)
 end
 
 end
diff --git a/lib/rbvmomi/sms.rb b/lib/rbvmomi/sms.rb
index 98d12ec6..8a579e6f 100644
--- a/lib/rbvmomi/sms.rb
+++ b/lib/rbvmomi/sms.rb
@@ -54,7 +54,7 @@ def pretty_print pp
   end
 
   add_extension_dir File.join(File.dirname(__FILE__), "sms")
-  load_vmodl(ENV['VMODL'] || File.join(File.dirname(__FILE__), "../../vmodl.db"))
+  load_vmodl(vmodl_filename)
 end
 
 end
diff --git a/lib/rbvmomi/type_loader.rb b/lib/rbvmomi/type_loader.rb
index ba93ed46..9f98500b 100644
--- a/lib/rbvmomi/type_loader.rb
+++ b/lib/rbvmomi/type_loader.rb
@@ -1,6 +1,7 @@
 # Copyright (c) 2010 VMware, Inc.  All Rights Reserved.
 require 'set'
 require 'monitor'
+require 'yaml'
 
 module RbVmomi
 
@@ -13,7 +14,12 @@ def initialize fn, extension_dirs, namespace
     @id2wsdl = {}
     @loaded = {}
     add_types Hash[BasicTypes::BUILTIN.map { |k| [k,nil] }]
-    vmodl_database = File.open(fn, 'r') { |io| Marshal.load io }
+    vmodl_database = case File.extname(fn)
+                     when '.yml', '.yaml'
+                       File.open(fn, 'r') { |io| YAML.load io }
+                     else
+                       File.open(fn, 'r') { |io| Marshal.load io }
+                     end
     vmodl_database.reject! { |k,v| k =~ /^_/ }
     add_types vmodl_database
     preload
diff --git a/lib/rbvmomi/vim.rb b/lib/rbvmomi/vim.rb
index 66626de8..d505f748 100644
--- a/lib/rbvmomi/vim.rb
+++ b/lib/rbvmomi/vim.rb
@@ -143,7 +143,7 @@ def get_log_keys host=nil
   add_extension_dir File.join(File.dirname(__FILE__), "vim")
   (ENV['RBVMOMI_VIM_EXTENSION_PATH']||'').split(':').each { |dir| add_extension_dir dir }
 
-  load_vmodl(ENV['VMODL'] || File.join(File.dirname(__FILE__), "../../vmodl.db"))
+  load_vmodl(vmodl_filename)
 end
 
 end