diff --git a/Gemfile b/Gemfile
index 96261d3..d621017 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,7 +4,7 @@ ruby '2.7.0'
 
 gem 'active_model_serializers', '0.10.7'
 gem 'pg'
-gem 'puma', '~> 3.12.2'
+gem 'puma', '~> 4.3.12'
 gem 'rack-cors'
 gem 'rails', '~> 5.0.0'
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 26a888d..1816c8c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -73,7 +73,8 @@ GEM
     nokogiri (1.10.8)
       mini_portile2 (~> 2.4.0)
     pg (0.18.4)
-    puma (3.12.2)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.2.2)
     rack-cors (1.0.5)
       rack (>= 1.6.0)
@@ -133,7 +134,7 @@ DEPENDENCIES
   active_model_serializers (= 0.10.7)
   listen
   pg
-  puma (~> 3.12.2)
+  puma (~> 4.3.12)
   rack-cors
   rails (~> 5.0.0)
   spring