diff --git a/backbonejs-examples/ex2/Gemfile.lock b/backbonejs-examples/ex2/Gemfile.lock
index c769fef..6780d64 100644
--- a/backbonejs-examples/ex2/Gemfile.lock
+++ b/backbonejs-examples/ex2/Gemfile.lock
@@ -32,18 +32,22 @@ GEM
     hiredis (0.3.2)
     json (1.4.6)
     multi_json (1.1.0)
-    rack (1.4.1)
-    rack-protection (1.2.0)
+    mustermann (2.0.2)
+      ruby2_keywords (~> 0.0.1)
+    rack (2.2.4)
+    rack-protection (2.2.3)
       rack
     redis (2.2.2)
+    ruby2_keywords (0.0.5)
     shotgun (0.9)
       rack (>= 1.0)
-    sinatra (1.3.2)
-      rack (~> 1.3, >= 1.3.6)
-      rack-protection (~> 1.2)
-      tilt (~> 1.3, >= 1.3.3)
+    sinatra (2.2.3)
+      mustermann (~> 2.0)
+      rack (~> 2.2)
+      rack-protection (= 2.2.3)
+      tilt (~> 2.0)
     stringex (1.2.2)
-    tilt (1.3.3)
+    tilt (2.0.11)
     uuidtools (2.1.2)
 
 PLATFORMS