diff --git a/Gemfile b/Gemfile
index 225602dd..4421004f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -145,7 +145,7 @@ end
 
 # Use unicorn as the app server
 # gem 'unicorn'
-gem 'puma'
+gem 'puma', '~> 4.3.10'
 
 # Deploy with Capistrano
 # gem 'capistrano'
diff --git a/Gemfile.lock b/Gemfile.lock
index fc6911e2..513db351 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -342,7 +342,7 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (4.0.6)
-    puma (5.6.1)
+    puma (4.3.10)
       nio4r (~> 2.0)
     racc (1.6.0)
     rack (2.2.3)
@@ -522,7 +522,7 @@ DEPENDENCIES
   poltergeist
   pry-doc
   pry-rails
-  puma
+  puma (~> 4.3.10)
   rack-cors
   rails (~> 6.1.0)
   rqrcode