diff --git a/flipped-demos/ch03-saas/sinatra/Gemfile.lock b/flipped-demos/ch03-saas/sinatra/Gemfile.lock
index 6e5c9bb..16e436a 100644
--- a/flipped-demos/ch03-saas/sinatra/Gemfile.lock
+++ b/flipped-demos/ch03-saas/sinatra/Gemfile.lock
@@ -2,17 +2,30 @@ GEM
   remote: https://rubygems.org/
   specs:
     base64 (0.2.0)
+    ffi (1.17.4)
+    ffi (1.17.4-x86_64-linux-gnu)
+    listen (3.10.0)
+      logger
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
+    logger (1.7.0)
     mustermann (3.0.3)
       ruby2_keywords (~> 0.0.1)
-    rack (3.1.7)
+    rack (3.2.6)
     rack-protection (4.0.0)
       base64 (>= 0.1.0)
       rack (>= 3.0.0, < 4)
-    rack-session (2.0.0)
+    rack-session (2.1.2)
+      base64 (>= 0.1.0)
       rack (>= 3.0.0)
     rackup (2.1.0)
       rack (>= 3)
       webrick (~> 1.8)
+    rb-fsevent (0.11.2)
+    rb-inotify (0.11.1)
+      ffi (~> 1.0)
+    rerun (0.14.0)
+      listen (~> 3.0)
     ruby2_keywords (0.0.5)
     sinatra (4.0.0)
       mustermann (~> 3.0)
@@ -27,9 +40,11 @@ GEM
 
 PLATFORMS
   ruby
+  x86_64-linux
 
 DEPENDENCIES
   rackup
+  rerun
   sinatra (~> 4.0)
   sinatra-flash