diff --git a/Gemfile b/Gemfile
index 29d639b9a..84c658ab3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 ruby '>= 2.5.0', '< 3.2.0'
 gem 'bundler', '>= 1.12.0'
 
-gem 'rails', '6.1.6'
+gem 'rails', '6.1.6.1'
 gem 'globalid', '~> 0.4.2' if Gem.ruby_version < Gem::Version.new('2.6.0')
 gem 'rouge', '~> 3.28.0'
 gem 'request_store', '~> 1.5.0'
@@ -22,6 +22,8 @@ gem 'rubyzip', '~> 2.3.0'
 gem 'net-smtp', '~> 0.3.0'
 gem 'net-imap', '~> 0.2.2'
 gem 'net-pop', '~> 0.1.1'
+# Rails 6.1.6.1 does not work with Pysch 3.0.2, which is installed by default with Ruby 2.5. See https://github.com/rails/rails/issues/45590
+gem 'psych', '>= 3.1.0' if Gem.ruby_version < Gem::Version.new('2.6.0')
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :x64_mingw, :mswin]
diff --git a/config/application.rb b/config/application.rb
index bba468f38..0a2d2f1fc 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -32,6 +32,10 @@ module RedmineApp
 
     config.active_record.store_full_sti_class = true
     config.active_record.default_timezone = :local
+    config.active_record.yaml_column_permitted_classes = [
+      Symbol,
+      ActiveSupport::HashWithIndifferentAccess
+    ]
 
     config.action_mailer.delivery_job = "ActionMailer::MailDeliveryJob"