diff --git a/Gemfile b/Gemfile
index 5049064..53ed2dc 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem 'jquery-rails'
 gem 'turbolinks', github: 'rails/turbolinks'
 # Pin Puma to a recent-ish version that supports OpenSSL, which is
 # what the CircleCI environment has.
-gem 'puma', '~> 5.4'
+gem 'puma', '~> 5.5'
 
 group :test do
   gem 'capybara', '~>3.35'
diff --git a/Gemfile.lock b/Gemfile.lock
index 4440ef2..c32da2b 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -93,13 +93,13 @@ GEM
     mini_mime (1.1.0)
     mini_portile2 (2.5.3)
     minitest (5.14.4)
-    nio4r (2.5.7)
+    nio4r (2.5.8)
     nokogiri (1.11.6)
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
     percy-capybara (4.3.3)
     public_suffix (4.0.6)
-    puma (5.4.0)
+    puma (5.5.1)
       nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
@@ -184,7 +184,7 @@ DEPENDENCIES
   database_cleaner
   jquery-rails
   percy-capybara (~> 4.3.3)
-  puma (~> 5.4)
+  puma (~> 5.5)
   rails (~> 5.2.6)
   rails_12factor
   sass-rails