diff --git a/Gemfile b/Gemfile
index ea4e7bb..1bedac1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,7 +15,7 @@ gem 'coveralls', require: false
 gem 'pg'
 
 # Use Puma as the app server
-gem 'puma', '~> 3.12'
+gem 'puma', '~> 4.1'
 # 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 ad5c27f..c9070cc 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -139,7 +139,8 @@ GEM
     orm_adapter (0.5.0)
     pg (1.1.3)
     public_suffix (3.0.3)
-    puma (3.12.0)
+    puma (4.1.0)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -264,7 +265,7 @@ DEPENDENCIES
   letter_opener
   listen (>= 3.0.5, < 3.2)
   pg
-  puma (~> 3.12)
+  puma (~> 4.1)
   rails (~> 5.2.2)
   rails_real_favicon
   sass-rails (~> 5.0)