diff --git a/Gemfile b/Gemfile
index 831abd5..4928f13 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.1'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+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 90c20d6..819e21c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -294,7 +294,7 @@ GEM
       activerecord (>= 4.2, < 5.3)
       request_store (~> 1.1)
     public_suffix (3.0.3)
-    puma (3.12.0)
+    puma (3.12.2)
     pxlsrt (1.8.2)
       oily_png (~> 1.2.1)
       thor (~> 0.18)
@@ -488,7 +488,7 @@ DEPENDENCIES
   mirador_rails (~> 0.6.0)
   nouislider-rails
   oily_png
-  puma (~> 3.11)
+  puma (~> 3.12)
   pxlsrt
   rails (~> 5.2.1)
   rest-client