diff --git a/api/ruby/building-a-ci-server/Gemfile b/api/ruby/building-a-ci-server/Gemfile
index a92a19a98..b93d3fa42 100644
--- a/api/ruby/building-a-ci-server/Gemfile
+++ b/api/ruby/building-a-ci-server/Gemfile
@@ -1,6 +1,6 @@
 source "http://rubygems.org"
 
 gem "json",        "~> 2.3"
-gem 'sinatra',     '~> 1.3.5'
+gem 'sinatra',     '~> 2.2.0'
 gem "shotgun"
 gem "octokit",     '~> 3.0'
diff --git a/api/ruby/building-a-ci-server/Gemfile.lock b/api/ruby/building-a-ci-server/Gemfile.lock
index b161fb7dc..e86351f3d 100644
--- a/api/ruby/building-a-ci-server/Gemfile.lock
+++ b/api/ruby/building-a-ci-server/Gemfile.lock
@@ -6,21 +6,25 @@ GEM
       multipart-post (>= 1.2, < 3)
     json (2.3.0)
     multipart-post (2.0.0)
+    mustermann (1.1.1)
+      ruby2_keywords (~> 0.0.1)
     octokit (3.0.0)
       sawyer (~> 0.5.3)
-    rack (1.6.13)
-    rack-protection (1.5.5)
+    rack (2.2.3)
+    rack-protection (2.2.0)
       rack
+    ruby2_keywords (0.0.5)
     sawyer (0.5.4)
       addressable (~> 2.3.5)
       faraday (~> 0.8, < 0.10)
     shotgun (0.9)
       rack (>= 1.0)
-    sinatra (1.3.6)
-      rack (~> 1.4)
-      rack-protection (~> 1.3)
-      tilt (~> 1.3, >= 1.3.3)
-    tilt (1.4.1)
+    sinatra (2.2.0)
+      mustermann (~> 1.0)
+      rack (~> 2.2)
+      rack-protection (= 2.2.0)
+      tilt (~> 2.0)
+    tilt (2.0.10)
 
 PLATFORMS
   ruby
@@ -29,7 +33,7 @@ DEPENDENCIES
   json (~> 2.3)
   octokit (~> 3.0)
   shotgun
-  sinatra (~> 1.3.5)
+  sinatra (~> 2.2.0)
 
 BUNDLED WITH
    1.11.2