diff --git a/Gemfile.lock b/Gemfile.lock
index ab9255b..7300f8c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -74,7 +74,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
     psych (3.0.2)
-    rack (2.0.4)
+    rack (2.2.3)
     rake (12.3.1)
     rb-fsevent (0.10.3)
     rb-inotify (0.9.10)