diff --git a/assets/ruby_simple/Gemfile b/assets/ruby_simple/Gemfile
index 04416be..49ad5aa 100644
--- a/assets/ruby_simple/Gemfile
+++ b/assets/ruby_simple/Gemfile
@@ -1,4 +1,4 @@
 source 'https://rubygems.org'
 
-gem 'rack', '~> 2.0'
+gem 'rack', '~> 2.1'
 gem 'sinatra'
diff --git a/assets/ruby_simple/Gemfile.lock b/assets/ruby_simple/Gemfile.lock
index 3bbe525..c6c07bd 100644
--- a/assets/ruby_simple/Gemfile.lock
+++ b/assets/ruby_simple/Gemfile.lock
@@ -2,7 +2,7 @@ GEM
   remote: https://rubygems.org/
   specs:
     mustermann (1.0.3)
-    rack (2.1.1)
+    rack (2.1.4)
     rack-protection (2.0.5)
       rack
     sinatra (2.0.5)
@@ -16,7 +16,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  rack (~> 2.0)
+  rack (~> 2.1)
   sinatra
 
 BUNDLED WITH