diff --git a/app/Gemfile b/app/Gemfile
index a99d1c7..ce57558 100644
--- a/app/Gemfile
+++ b/app/Gemfile
@@ -2,4 +2,4 @@
 
 source "https://rubygems.org"
 
-gem "sinatra", "2.0.1"
\ No newline at end of file
+gem "sinatra", "4.1.0"
\ No newline at end of file
diff --git a/app/Gemfile.lock b/app/Gemfile.lock
index 90a15c6..7f77ff8 100644
--- a/app/Gemfile.lock
+++ b/app/Gemfile.lock
@@ -1,24 +1,32 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    mustermann (1.1.1)
+    base64 (0.2.0)
+    logger (1.6.1)
+    mustermann (3.0.3)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.3)
-    rack-protection (2.0.1)
-      rack
-    ruby2_keywords (0.0.2)
-    sinatra (2.0.1)
-      mustermann (~> 1.0)
-      rack (~> 2.0)
-      rack-protection (= 2.0.1)
+    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)
-    tilt (2.0.10)
+    tilt (2.4.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
-  sinatra (= 2.0.1)
+  sinatra (= 4.1.0)
 
 BUNDLED WITH
-   1.17.2
+   1.17.3