diff --git a/Gemfile b/Gemfile
index faa2700..6d87686 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem 'rails', '~> 5.1.1'
 # Use postgresql as the database for Active Record
 gem 'pg', '~> 0.18'
 # Use Puma as the app server
-gem 'puma', '~> 3.0'
+gem 'puma', '~> 4.3'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
 gem 'jbuilder', '~> 2.5'
 # Use Redis adapter to run Action Cable in production
diff --git a/Gemfile.lock b/Gemfile.lock
index fb0521e..722e24e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -86,7 +86,8 @@ GEM
     pry (0.12.2)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
-    puma (3.12.0)
+    puma (4.3.12)
+      nio4r (~> 2.0)
     rack (2.0.6)
     rack-cors (1.0.2)
     rack-test (1.1.0)
@@ -160,7 +161,7 @@ DEPENDENCIES
   listen (~> 3.0.5)
   pg (~> 0.18)
   pry
-  puma (~> 3.0)
+  puma (~> 4.3)
   rack-cors
   rails (~> 5.1.1)
   simple_token_authentication (~> 1.0)