diff --git a/Gemfile b/Gemfile
index 22b2a934a..c0df6c3b6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,7 +4,7 @@ git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
 gem 'rails', '~> 5.2.0'
 gem 'mysql2', '>= 0.4.4', '< 0.6.0'
-gem 'puma', '~> 3.11'
+gem 'puma', '~> 5.6.5'
 gem 'sass-rails', '~> 5.0'
 gem 'uglifier', '>= 1.3.0'
 
@@ -53,7 +53,7 @@ gem 'acts_as_list'
 gem 'omniauth-cas'
 
 # profiler Middleware
-gem 'rack-mini-profiler'
+# gem 'rack-mini-profiler'
 
 # object-based searching
 gem 'ransack'