diff --git a/Gemfile b/Gemfile
index 41f8b90..3d39c4f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,5 +1,5 @@
 source "https://rubygems.org"
 
 
-gem "sinatra", "~>1.4.7"
+gem "sinatra", "~>4.1.0"
 gem "sinatra-contrib"
diff --git a/Gemfile.lock b/Gemfile.lock
index fde6214..7dd3d82 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,31 +1,39 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    backports (3.15.0)
+    base64 (0.2.0)
+    logger (1.6.1)
     multi_json (1.14.1)
-    rack (1.6.12)
-    rack-protection (1.5.5)
-      rack
-    rack-test (1.1.0)
-      rack (>= 1.0, < 3)
-    sinatra (1.4.8)
-      rack (~> 1.5)
-      rack-protection (~> 1.4)
-      tilt (>= 1.3, < 3)
-    sinatra-contrib (1.4.7)
-      backports (>= 2.0)
-      multi_json
-      rack-protection
-      rack-test
-      sinatra (~> 1.4.0)
-      tilt (>= 1.3, < 3)
-    tilt (2.0.10)
+    mustermann (3.0.3)
+      ruby2_keywords (~> 0.0.1)
+    rack (3.1.8)
+    rack-protection (4.1.0)
+      base64 (>= 0.1.0)
+      logger (>= 1.6.0)
+      rack (>= 3.0.0, < 4)
+    rack-session (2.0.0)
+      rack (>= 3.0.0)
+    ruby2_keywords (0.0.5)
+    sinatra (4.1.0)
+      logger (>= 1.6.0)
+      mustermann (~> 3.0)
+      rack (>= 3.0.0, < 4)
+      rack-protection (= 4.1.0)
+      rack-session (>= 2.0.0, < 3)
+      tilt (~> 2.0)
+    sinatra-contrib (4.1.0)
+      multi_json (>= 0.0.2)
+      mustermann (~> 3.0)
+      rack-protection (= 4.1.0)
+      sinatra (= 4.1.0)
+      tilt (~> 2.0)
+    tilt (2.4.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  sinatra (~> 1.4.7)
+  sinatra (~> 4.1.0)
   sinatra-contrib
 
 BUNDLED WITH