diff --git a/Gemfile b/Gemfile
index 211c9ce..2e948f5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,7 +10,7 @@ gem 'rails', '~> 5.2.3'
 # Use postgresql as the database for Active Record
 gem 'pg', '>= 0.18', '< 2.0'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 gem 'devise'
 gem 'pundit'
diff --git a/Gemfile.lock b/Gemfile.lock
index 56acb1e..03b4d85 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -85,7 +85,8 @@ GEM
       racc (~> 1.4)
     orm_adapter (0.5.0)
     pg (1.2.3)
-    puma (3.12.6)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     pundit (2.1.1)
       activesupport (>= 3.0.0)
     racc (1.5.2)
@@ -161,7 +162,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   pundit
   rack-cors
   rails (~> 5.2.3)