diff --git a/Gemfile b/Gemfile
index 6c6337d..43ead11 100644
--- a/Gemfile
+++ b/Gemfile
@@ -30,3 +30,5 @@ gem "wdm", "~> 0.1.1", :platforms => [:mingw, :x64_mingw, :mswin]
 
 
 gem "webrick", "~> 1.7"
+
+gem "psych", "~> 5.1"