diff --git a/spec/app/rails_5.2/Gemfile b/spec/app/rails_5.2/Gemfile
index 9abebf92..c0e6cb39 100644
--- a/spec/app/rails_5.2/Gemfile
+++ b/spec/app/rails_5.2/Gemfile
@@ -5,7 +5,7 @@ gem 'rails', '~> 5.2.2'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use Puma as the app server
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 4.3.8'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets