diff --git a/Gemfile b/Gemfile
index ba5bd29..d9a0c57 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,4 +4,4 @@ gem "rake"
 gem "rspec"
 gem "redis"
 gem "curb"
-gem "sinatra"
+gem "sinatra", ">= 2.2.0"
diff --git a/Gemfile.lock b/Gemfile.lock
index fd0e3a0..0b68c4b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -6,7 +6,7 @@ GEM
     mustermann (1.1.1)
       ruby2_keywords (~> 0.0.1)
     rack (2.2.3)
-    rack-protection (2.0.8.1)
+    rack-protection (2.2.0)
       rack
     rake (13.0.1)
     redis (4.2.1)
@@ -23,11 +23,11 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
     rspec-support (3.9.3)
-    ruby2_keywords (0.0.2)
-    sinatra (2.0.8.1)
+    ruby2_keywords (0.0.5)
+    sinatra (2.2.0)
       mustermann (~> 1.0)
-      rack (~> 2.0)
-      rack-protection (= 2.0.8.1)
+      rack (~> 2.2)
+      rack-protection (= 2.2.0)
       tilt (~> 2.0)
     tilt (2.0.10)
 
@@ -39,7 +39,7 @@ DEPENDENCIES
   rake
   redis
   rspec
-  sinatra
+  sinatra (>= 2.2.0)
 
 BUNDLED WITH
    2.1.4