diff --git a/Gemfile.lock b/Gemfile.lock
index 502f99b..b2aba7a 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -23,7 +23,6 @@ GEM
       zeitwerk (~> 2.2, >= 2.2.2)
     addressable (2.7.0)
       public_suffix (>= 2.0.2, < 5.0)
-    backports (3.16.1)
     chronic (0.10.2)
     coderay (1.1.2)
     concurrent-ruby (1.1.6)
@@ -62,9 +61,9 @@ GEM
       mime-types-data (~> 3.2015)
     mime-types-data (3.2019.1009)
     minitest (5.14.1)
-    multi_json (1.14.1)
+    multi_json (1.15.0)
     multipart-post (2.1.1)
-    mustermann (1.1.1)
+    mustermann (3.0.0)
       ruby2_keywords (~> 0.0.1)
     netrc (0.11.0)
     nio4r (2.5.2)
@@ -76,8 +75,8 @@ GEM
     public_suffix (4.0.3)
     puma (4.3.5)
       nio4r (~> 2.0)
-    rack (2.2.3)
-    rack-protection (2.0.8.1)
+    rack (2.2.4)
+    rack-protection (3.0.4)
       rack
     rake (13.0.1)
     recursive-open-struct (1.1.0)
@@ -86,22 +85,21 @@ GEM
       http-cookie (>= 1.0.2, < 2.0)
       mime-types (>= 1.16, < 4.0)
       netrc (~> 0.8)
-    ruby2_keywords (0.0.2)
-    sinatra (2.0.8.1)
-      mustermann (~> 1.0)
-      rack (~> 2.0)
-      rack-protection (= 2.0.8.1)
+    ruby2_keywords (0.0.5)
+    sinatra (3.0.4)
+      mustermann (~> 3.0)
+      rack (~> 2.2, >= 2.2.4)
+      rack-protection (= 3.0.4)
       tilt (~> 2.0)
-    sinatra-contrib (2.0.8.1)
-      backports (>= 2.8.2)
+    sinatra-contrib (3.0.4)
       multi_json
-      mustermann (~> 1.0)
-      rack-protection (= 2.0.8.1)
-      sinatra (= 2.0.8.1)
+      mustermann (~> 3.0)
+      rack-protection (= 3.0.4)
+      sinatra (= 3.0.4)
       tilt (~> 2.0)
     thor (1.0.1)
     thread_safe (0.3.6)
-    tilt (2.0.10)
+    tilt (2.0.11)
     tzinfo (1.2.7)
       thread_safe (~> 0.1)
     unf (0.1.4)