diff --git a/Gemfile b/Gemfile
index d7d99ed..830f56a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,7 +7,7 @@ end
 
 gem 'rails', '~> 5.0.5'
 gem 'sqlite3'
-gem 'puma', '~> 3.0'
+gem 'puma', '~> 3.12'
 gem 'sass-rails', '~> 5.0'
 gem 'simple_form', '~> 3.5'
 gem 'bootstrap-sass', '~> 3.3', '>= 3.3.6'
diff --git a/Gemfile.lock b/Gemfile.lock
index ff77988..383e7b5 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -105,7 +105,7 @@ GEM
       cocaine (~> 0.5.5)
       mime-types
       mimemagic (= 0.3.0)
-    puma (3.10.0)
+    puma (3.12.3)
     rack (2.0.3)
     rack-test (0.6.3)
       rack (>= 1.0)
@@ -199,7 +199,7 @@ DEPENDENCIES
   jquery-rails
   listen (~> 3.0.5)
   paperclip (~> 4.3, >= 4.3.6)
-  puma (~> 3.0)
+  puma (~> 3.12)
   rails (~> 5.0.5)
   sass-rails (~> 5.0)
   simple_form (~> 3.5)