diff --git a/todo/Gemfile b/todo/Gemfile
index 406e8d8..ac6ca37 100644
--- a/todo/Gemfile
+++ b/todo/Gemfile
@@ -8,7 +8,7 @@ gem 'rails', '~> 5.2.3'
 # 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/todo/Gemfile.lock b/todo/Gemfile.lock
index 8764360..00a382c 100644
--- a/todo/Gemfile.lock
+++ b/todo/Gemfile.lock
@@ -108,7 +108,7 @@ GEM
     nokogiri (1.10.8)
       mini_portile2 (~> 2.4.0)
     public_suffix (4.0.1)
-    puma (3.12.1)
+    puma (3.12.6)
     rack (2.0.7)
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
@@ -202,7 +202,7 @@ DEPENDENCIES
   jbuilder (~> 2.5)
   jquery-rails (~> 4.3.1)
   listen (>= 3.0.5, < 3.2)
-  puma (~> 3.11)
+  puma (~> 3.12)
   rails (~> 5.2.3)
   sass-rails (~> 5.0)
   selenium-webdriver