diff --git a/Gemfile.lock b/Gemfile.lock
index 4de9cff..751ba95 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -41,7 +41,7 @@ GEM
       coderay (~> 1.1.0)
       method_source (~> 0.8.1)
       slop (~> 3.4)
-    rack (1.6.4)
+    rack (2.2.3)
     rack-test (0.6.3)
       rack (>= 1.0)
     rspec (3.4.0)