diff --git a/Gemfile b/Gemfile
index 5cf25d29..7bef8d15 100644
--- a/Gemfile
+++ b/Gemfile
@@ -33,7 +33,7 @@ gem 'omniauth_openid_connect', '~> 0.3.5'
 gem 'omniauth-twitter', '~> 1.4.0'
 gem 'pagy', '~> 3.11.0'
 gem 'pluck_to_hash', '~> 1.0.2'
-gem 'puma', '~> 3.12.6'
+gem 'puma', '~> 4.3.8'
 gem 'rails', '~> 5.2.6'
 gem 'random_password', '~> 0.1.1'
 gem "recaptcha", '~> 5.7.0'
diff --git a/Gemfile.lock b/Gemfile.lock
index e2a1786c..a77a0bfb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -285,7 +285,8 @@ GEM
       activesupport (>= 4.0.2)
     popper_js (1.16.0)
     public_suffix (4.0.6)
-    puma (3.12.6)
+    puma (4.3.8)
+      nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
     rack-oauth2 (1.16.0)
@@ -495,7 +496,7 @@ DEPENDENCIES
   pagy (~> 3.11.0)
   pg (~> 0.18)
   pluck_to_hash (~> 1.0.2)
-  puma (~> 3.12.6)
+  puma (~> 4.3.8)
   rails (~> 5.2.6)
   rails-controller-testing (~> 1.0)
   random_password (~> 0.1.1)