diff --git a/Gemfile.lock b/Gemfile.lock
index fc06975..3166a4e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -44,7 +44,7 @@ GEM
       multi_xml (~> 0.5)
       rack (>= 1.2, < 3)
     psych (3.1.0)
-    rack (2.0.7)
+    rack (2.2.3)
     rake (12.3.2)
     rdoc (6.1.1)
     rspec (3.8.0)