diff --git a/Gemfile.lock b/Gemfile.lock
index ddee0cc..ecb952f 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -100,7 +100,7 @@ GEM
       coderay (~> 1.1)
       method_source (~> 1.0)
     public_suffix (6.0.2)
-    rack (3.1.16)
+    rack (3.1.21)
     rackup (2.2.1)
       rack (>= 3)
     rb-fsevent (0.11.2)