diff --git a/Gemfile b/Gemfile
index bd31f14..2cc61ad 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,7 +2,7 @@ source 'https://rubygems.org'
 ruby '2.7.3'
 
 gem 'thin', '1.8.0'
-gem 'sinatra', '2.1.0'
+gem 'sinatra', '2.2.3'
 gem 'maruku', '0.7.3'
 gem 'haml', '5.2.1'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 6156fe7..36d687d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -8,10 +8,10 @@ GEM
       temple (>= 0.8.0)
       tilt
     maruku (0.7.3)
-    mustermann (1.1.1)
+    mustermann (2.0.2)
       ruby2_keywords (~> 0.0.1)
-    rack (2.2.3)
-    rack-protection (2.1.0)
+    rack (2.2.4)
+    rack-protection (2.2.3)
       rack
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -28,20 +28,20 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.10.0)
     rspec-support (3.10.2)
-    ruby2_keywords (0.0.4)
+    ruby2_keywords (0.0.5)
     shotgun (0.9.2)
       rack (>= 1.0)
-    sinatra (2.1.0)
-      mustermann (~> 1.0)
+    sinatra (2.2.3)
+      mustermann (~> 2.0)
       rack (~> 2.2)
-      rack-protection (= 2.1.0)
+      rack-protection (= 2.2.3)
       tilt (~> 2.0)
     temple (0.8.2)
     thin (1.8.0)
       daemons (~> 1.0, >= 1.0.9)
       eventmachine (~> 1.0, >= 1.0.4)
       rack (>= 1, < 3)
-    tilt (2.0.10)
+    tilt (2.0.11)
 
 PLATFORMS
   ruby
@@ -53,7 +53,7 @@ DEPENDENCIES
   rack-test (= 1.1.0)
   rspec (= 3.10.0)
   shotgun (= 0.9.2)
-  sinatra (= 2.1.0)
+  sinatra (= 2.2.3)
   thin (= 1.8.0)
 
 RUBY VERSION