diff --git a/appengine/endpoints/Gemfile.lock b/appengine/endpoints/Gemfile.lock
index f20d7d1ee..95038b5ca 100644
--- a/appengine/endpoints/Gemfile.lock
+++ b/appengine/endpoints/Gemfile.lock
@@ -25,7 +25,7 @@ GEM
       uri
     netrc (0.11.0)
     public_suffix (5.0.4)
-    rack (3.0.9.1)
+    rack (3.1.20)
     rack-cors (2.0.2)
       rack (>= 2.0.0)
     rack-protection (4.0.0)