diff --git a/Gemfile.lock b/Gemfile.lock
index 624f6fd..b89d0e6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -82,7 +82,7 @@ GEM
       rack (>= 1.2, < 3)
     polyglot (0.3.3)
     power_assert (1.1.1)
-    rack (1.6.8)
+    rack (2.2.3)
     rake (10.3.2)
     rdoc (4.3.0)
     redcarpet (3.4.0)