diff --git a/ruby/Gemfile b/ruby/Gemfile
index 78da4f7..e2f3f2d 100644
--- a/ruby/Gemfile
+++ b/ruby/Gemfile
@@ -1,5 +1,5 @@
 source "https://rubygems.org"
 
-gem 'sinatra', '2.0.8.1'
-gem 'sinatra-contrib', '2.0.8.1'
+gem 'sinatra', '3.0.4'
+gem 'sinatra-contrib', '3.0.4'
 gem 'sinatra-reloader', '~> 1.0'
diff --git a/ruby/Gemfile.lock b/ruby/Gemfile.lock
index c0b7925..ec677ff 100644
--- a/ruby/Gemfile.lock
+++ b/ruby/Gemfile.lock
@@ -1,36 +1,34 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    backports (3.18.1)
-    multi_json (1.14.1)
-    mustermann (1.1.1)
+    multi_json (1.15.0)
+    mustermann (3.0.0)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.3)
-    rack-protection (2.0.8.1)
+    rack (2.2.4)
+    rack-protection (3.0.4)
       rack
-    ruby2_keywords (0.0.2)
-    sinatra (2.0.8.1)
-      mustermann (~> 1.0)
-      rack (~> 2.0)
-      rack-protection (= 2.0.8.1)
+    ruby2_keywords (0.0.5)
+    sinatra (3.0.4)
+      mustermann (~> 3.0)
+      rack (~> 2.2, >= 2.2.4)
+      rack-protection (= 3.0.4)
       tilt (~> 2.0)
-    sinatra-contrib (2.0.8.1)
-      backports (>= 2.8.2)
+    sinatra-contrib (3.0.4)
       multi_json
-      mustermann (~> 1.0)
-      rack-protection (= 2.0.8.1)
-      sinatra (= 2.0.8.1)
+      mustermann (~> 3.0)
+      rack-protection (= 3.0.4)
+      sinatra (= 3.0.4)
       tilt (~> 2.0)
     sinatra-reloader (1.0)
       sinatra-contrib
-    tilt (2.0.10)
+    tilt (2.0.11)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  sinatra (= 2.0.8.1)
-  sinatra-contrib (= 2.0.8.1)
+  sinatra (= 3.0.4)
+  sinatra-contrib (= 3.0.4)
   sinatra-reloader (~> 1.0)
 
 BUNDLED WITH