diff --git a/Gemfile b/Gemfile
index 442c97d..75e142a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ 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'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
diff --git a/Gemfile.lock b/Gemfile.lock
index def077b..93d32d3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -208,7 +208,8 @@ GEM
     pg (1.1.4-x64-mingw32)
     popper_js (1.14.5)
     public_suffix (3.1.1)
-    puma (3.12.1)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     pundit (2.0.1)
       activesupport (>= 3.0.0)
     pusher (1.3.3)
@@ -358,7 +359,7 @@ DEPENDENCIES
   omniauth-google-oauth2
   omniauth-vkontakte
   pg (>= 0.18, < 2.0)
-  puma (~> 3.11)
+  puma (~> 4.3)
   pundit (~> 2.0.1)
   pusher (~> 1.3.3)
   rails (~> 5.2.3)