diff --git a/Gemfile.lock b/Gemfile.lock
index ab5d4c1..beafae1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -6,7 +6,7 @@ GEM
       rack (>= 1.6.0)
     cutest (1.2.3)
       clap
-    rack (2.1.4.1)
+    rack (2.2.6.4)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     tilt (2.0.10)