diff --git a/Gemfile b/Gemfile
index cc6ecac..3806185 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem 'rails', '~> 5.0.2'
 # Use postgresql as the database for Active Record
 gem 'pg', '~> 0.18'
 # Use Puma as the app server
-gem 'puma', '~> 3.0'
+gem 'puma', '~> 3.12'
 # 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 444d0a7..ea8a716 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -81,7 +81,7 @@ GEM
     nokogiri (1.7.0.1)
       mini_portile2 (~> 2.1.0)
     pg (0.19.0)
-    puma (3.7.1)
+    puma (3.12.6)
     rack (2.0.1)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -160,7 +160,7 @@ DEPENDENCIES
   jquery-rails
   listen (~> 3.0.5)
   pg (~> 0.18)
-  puma (~> 3.0)
+  puma (~> 3.12)
   rails (~> 5.0.2)
   sass-rails (~> 5.0)
   spring