diff --git a/Gemfile b/Gemfile
index 6a3f80a..f37b1a7 100644
--- a/Gemfile
+++ b/Gemfile
@@ -21,6 +21,7 @@ group :jekyll_plugins do
   gem "jekyll-livereload"
   gem "jekyll-polyglot"
   gem "jekyll-autoprefixer"
+  gem "wdm"
 end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem