diff --git a/ruby/examples/Gemfile.lock b/ruby/examples/Gemfile.lock
index ae07e2c..9da639f 100644
--- a/ruby/examples/Gemfile.lock
+++ b/ruby/examples/Gemfile.lock
@@ -3,7 +3,7 @@ GEM
   specs:
     metaparticle (0.0.0.13)
     mustermann (1.0.1)
-    rack (2.0.3)
+    rack (2.2.3)
     rack-protection (2.0.0)
       rack
     sinatra (2.0.0)