diff --git a/Gemfile b/Gemfile
old mode 100755
new mode 100644
index 94c1ac6..1706a3c
--- a/Gemfile
+++ b/Gemfile
@@ -14,7 +14,7 @@ gem 'rails', '~> 6.0.1'
 # Use postgresql as the database for Active Record
 gem 'pg', '~> 0.18'
 # Use Puma as the app server
-gem 'puma', '~> 3.7'
+gem 'puma', '~> 4.3', '>= 4.3.12'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0.7'
 # Use Uglifier as compressor for JavaScript assets