diff --git a/flipped-demos/ch03-saas/sinatra-sessions/Gemfile.lock b/flipped-demos/ch03-saas/sinatra-sessions/Gemfile.lock
index 72fa979..cb3cc87 100644
--- a/flipped-demos/ch03-saas/sinatra-sessions/Gemfile.lock
+++ b/flipped-demos/ch03-saas/sinatra-sessions/Gemfile.lock
@@ -19,7 +19,7 @@ GEM
     logger (1.7.0)
     mustermann (3.0.4)
       ruby2_keywords (~> 0.0.1)
-    rack (3.2.1)
+    rack (3.2.6)
     rack-protection (4.1.1)
       base64 (>= 0.1.0)
       logger (>= 1.6.0)