diff --git a/Gemfile b/Gemfile
index 129149897..3fb702dcc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,2 +1,5 @@
 source "https://rubygems.org"
-gemspec
\ No newline at end of file
+gem "webrick", "~>1.7"
+gem "kramdown-parser-gfm", "~>1.1"
+gem "wdm", "~> 0.1.0" if Gem.win_platform?
+gemspec