diff --git a/Gemfile b/Gemfile
index cb27a4bf..6b0c43bd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ group :production, :development, :test do
   # Use sqlite3 as the database for Active Record
   gem 'sqlite3', '~> 1.3.13'
   # Use Puma as the app server
-  gem 'puma', '~> 3.7'
+  gem 'puma', '~> 5.5'
   # 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 4e14a1ea..e35da04c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -647,7 +647,8 @@ GEM
     powerpack (0.1.2)
     public_suffix (3.0.3)
     pul_uv_rails (2.0.1)
-    puma (3.12.1)
+    puma (5.5.1)
+      nio4r (~> 2.0)
     qa (2.2.0)
       activerecord-import
       deprecation
@@ -989,7 +990,7 @@ DEPENDENCIES
   omniauth-saml
   orcid!
   pdfjs_viewer-rails!
-  puma (~> 3.7)
+  puma (~> 5.5)
   rack-attack
   rails (~> 5.1.6.1)
   redis (~> 4.0)