diff --git a/Gemfile.lock b/Gemfile.lock
index fe0a8c5..3faa1c0 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -55,7 +55,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    rack (1.6.4)
+    rack (2.2.3)
     rack-accept (0.4.5)
       rack (>= 0.4)
     rack-mount (0.8.3)