diff --git a/Gemfile.lock b/Gemfile.lock
index 2f0e2e01..fc9ac848 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -133,7 +133,7 @@ GEM
     parslet (2.0.0)
     public_suffix (6.0.1)
     racc (1.8.1)
-    rack (3.1.20)
+    rack (3.1.21)
     rack-contrib (2.5.0)
       rack (< 4)
     rack-livereload (0.3.17)