diff --git a/docs/Gemfile b/docs/Gemfile
index d1eebc4..bfa55fe 100644
--- a/docs/Gemfile
+++ b/docs/Gemfile
@@ -2,7 +2,7 @@
 
 source "https://rubygems.org"
 
-gem 'wdm', '~> 0.1.1', :install_if => Gem.win_platform?
+gem 'wdm', '~> 0.2.0', :install_if => Gem.win_platform?
 
 gem "webrick"