diff --git a/ruby/Gemfile b/ruby/Gemfile
index 9d927f7..52ba5cc 100644
--- a/ruby/Gemfile
+++ b/ruby/Gemfile
@@ -1,6 +1,6 @@
 source 'https://rubygems.org'
 
-gem 'sinatra', '~> 1.4', '>= 1.4.6'
+gem 'sinatra', '~> 2.2', '>= 2.2.0'
 gem 'sqlite3', '~> 1.3', '>= 1.3.11'
 gem 'config', '~> 1.0'
 gem 'blockchain', '~> 3.0.1', '>= 1.1.1'
diff --git a/ruby/Gemfile.lock b/ruby/Gemfile.lock
index c5572e0..243ba8c 100644
--- a/ruby/Gemfile.lock
+++ b/ruby/Gemfile.lock
@@ -15,18 +15,22 @@ GEM
     i18n (0.7.0)
     json (1.8.5)
     minitest (5.8.3)
-    rack (1.6.4)
-    rack-protection (1.5.3)
+    mustermann (1.1.1)
+      ruby2_keywords (~> 0.0.1)
+    rack (2.2.3)
+    rack-protection (2.2.0)
       rack
+    ruby2_keywords (0.0.5)
     shotgun (0.9.1)
       rack (>= 1.0)
-    sinatra (1.4.6)
-      rack (~> 1.4)
-      rack-protection (~> 1.4)
-      tilt (>= 1.3, < 3)
+    sinatra (2.2.0)
+      mustermann (~> 1.0)
+      rack (~> 2.2)
+      rack-protection (= 2.2.0)
+      tilt (~> 2.0)
     sqlite3 (1.3.11)
     thread_safe (0.3.5)
-    tilt (2.0.1)
+    tilt (2.0.10)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
 
@@ -37,8 +41,8 @@ DEPENDENCIES
   blockchain (~> 3.0.1, >= 1.1.1)
   config (~> 1.0)
   shotgun (~> 0.9.1)
-  sinatra (~> 1.4, >= 1.4.6)
+  sinatra (~> 2.2, >= 2.2.0)
   sqlite3 (~> 1.3, >= 1.3.11)
 
 BUNDLED WITH
-   1.15.1
+   1.17.3