diff --git a/Gemfile b/Gemfile
index a6cfe07..054b0f2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,7 +5,7 @@ source "https://rubygems.org"
 git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
 
 gem "sinatra", "2.0.1"
-gem "puma", "4.2.1" 
+gem "puma", "4.3.12"
 gem 'puma-metrics'
 
 group :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index ccc5069..12650a4 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -4,12 +4,12 @@ GEM
     diff-lcs (1.3)
     mustermann (1.1.1)
       ruby2_keywords (~> 0.0.1)
-    nio4r (2.5.2)
-    prometheus-client (0.10.0)
-    puma (4.2.1)
+    nio4r (2.5.8)
+    prometheus-client (4.0.0)
+    puma (4.3.12)
       nio4r (~> 2.0)
-    puma-metrics (1.1.0)
-      prometheus-client (~> 0.10)
+    puma-metrics (1.2.4)
+      prometheus-client (>= 0.10)
       puma (>= 3.0)
     rack (2.2.2)
     rack-protection (2.0.1)
@@ -42,7 +42,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
-  puma (= 4.2.1)
+  puma (= 4.3.12)
   puma-metrics
   rack-test
   rake