diff --git a/Gemfile b/Gemfile
index c1f1ee3e2..cafac68a1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -19,7 +19,7 @@ gem 'rails', '~> 5.1.4'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+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 3b212e9b7..f718d5663 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -125,8 +125,10 @@ GEM
       mini_portile2 (~> 2.3.0)
     orm_adapter (0.5.0)
     public_suffix (3.0.2)
-    puma (3.12.0)
-    puma (3.12.0-java)
+    puma (4.3.11)
+      nio4r (~> 2.0)
+    puma (4.3.11-java)
+      nio4r (~> 2.0)
     rack (2.0.5)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -260,7 +262,7 @@ DEPENDENCIES
   ffaker
   jbuilder (~> 2.5)
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.7)
+  puma (~> 4.3)
   rails (~> 5.1.4)
   rails-controller-testing
   rspec-rails (~> 3.7)