diff --git a/Gemfile b/Gemfile
index 53e8b32..a45ec8e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,6 @@
 source "http://rubygems.org/"
 ruby "2.7.6"
 
-gem "sinatra", "~> 2.2.0"
+gem "sinatra", "~> 2.2.3"
 gem "puma", "~> 5.6.4"
 gem "rack-timeout", "~> 0.6.0"
diff --git a/Gemfile.lock b/Gemfile.lock
index 2f49f18..be867bc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,22 +1,22 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    mustermann (1.1.1)
+    mustermann (2.0.2)
       ruby2_keywords (~> 0.0.1)
     nio4r (2.5.8)
     puma (5.6.4)
       nio4r (~> 2.0)
-    rack (2.2.3.1)
-    rack-protection (2.2.0)
+    rack (2.2.4)
+    rack-protection (2.2.3)
       rack
     rack-timeout (0.6.0)
     ruby2_keywords (0.0.5)
-    sinatra (2.2.0)
-      mustermann (~> 1.0)
+    sinatra (2.2.3)
+      mustermann (~> 2.0)
       rack (~> 2.2)
-      rack-protection (= 2.2.0)
+      rack-protection (= 2.2.3)
       tilt (~> 2.0)
-    tilt (2.0.10)
+    tilt (2.0.11)
 
 PLATFORMS
   ruby
@@ -24,7 +24,7 @@ PLATFORMS
 DEPENDENCIES
   puma (~> 5.6.4)
   rack-timeout (~> 0.6.0)
-  sinatra (~> 2.2.0)
+  sinatra (~> 2.2.3)
 
 RUBY VERSION
    ruby 2.7.6p219