diff --git a/appengine/hello_world/Gemfile.lock b/appengine/hello_world/Gemfile.lock
index eb79510b7..94c4ab490 100644
--- a/appengine/hello_world/Gemfile.lock
+++ b/appengine/hello_world/Gemfile.lock
@@ -4,7 +4,7 @@ GEM
     diff-lcs (1.5.0)
     mustermann (3.0.0)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.8.1)
+    rack (2.2.23)
     rack-protection (3.1.0)
       rack (~> 2.2, >= 2.2.4)
     rack-test (2.1.0)