diff --git a/appengine/rails-cloudsql-mysql/Gemfile.lock b/appengine/rails-cloudsql-mysql/Gemfile.lock
index 1d68e8fe8..9bae0023c 100644
--- a/appengine/rails-cloudsql-mysql/Gemfile.lock
+++ b/appengine/rails-cloudsql-mysql/Gemfile.lock
@@ -233,7 +233,7 @@ GEM
     puma (6.3.1)
       nio4r (~> 2.0)
     racc (1.8.1)
-    rack (3.0.12)
+    rack (3.1.20)
     rack-session (2.0.0)
       rack (>= 3.0.0)
     rack-test (2.1.0)