diff --git a/functional_rack/Gemfile.lock b/functional_rack/Gemfile.lock
index 317c76c..f5303d6 100644
--- a/functional_rack/Gemfile.lock
+++ b/functional_rack/Gemfile.lock
@@ -1,7 +1,7 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    rack (2.2.2)
+    rack (2.2.3.1)
 
 PLATFORMS
   ruby