diff --git a/web/documentserver-example/ruby/Gemfile b/web/documentserver-example/ruby/Gemfile
index a31eca56..45e26a0c 100644
--- a/web/documentserver-example/ruby/Gemfile
+++ b/web/documentserver-example/ruby/Gemfile
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 source 'https://rubygems.org'
 
 gem 'byebug', '~> 11.1', groups: %i[development test]
diff --git a/web/documentserver-example/ruby/Rakefile b/web/documentserver-example/ruby/Rakefile
index 3c3cea86..bb892095 100644
--- a/web/documentserver-example/ruby/Rakefile
+++ b/web/documentserver-example/ruby/Rakefile
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require 'rake/testtask'
 require_relative 'config/application'
 
diff --git a/web/documentserver-example/ruby/app/controllers/application_controller.rb b/web/documentserver-example/ruby/app/controllers/application_controller.rb
index 32ce5cfd..b6d3299e 100644
--- a/web/documentserver-example/ruby/app/controllers/application_controller.rb
+++ b/web/documentserver-example/ruby/app/controllers/application_controller.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/controllers/home_controller.rb b/web/documentserver-example/ruby/app/controllers/home_controller.rb
index d331e595..81e8b0a6 100755
--- a/web/documentserver-example/ruby/app/controllers/home_controller.rb
+++ b/web/documentserver-example/ruby/app/controllers/home_controller.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/helpers/application_helper.rb b/web/documentserver-example/ruby/app/helpers/application_helper.rb
index d17fe1b8..3e7976e0 100644
--- a/web/documentserver-example/ruby/app/helpers/application_helper.rb
+++ b/web/documentserver-example/ruby/app/helpers/application_helper.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/helpers/home_helper.rb b/web/documentserver-example/ruby/app/helpers/home_helper.rb
index a0e2faf0..421fa078 100644
--- a/web/documentserver-example/ruby/app/helpers/home_helper.rb
+++ b/web/documentserver-example/ruby/app/helpers/home_helper.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/models/document_helper.rb b/web/documentserver-example/ruby/app/models/document_helper.rb
index e160abe8..0971ab72 100755
--- a/web/documentserver-example/ruby/app/models/document_helper.rb
+++ b/web/documentserver-example/ruby/app/models/document_helper.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/models/file_model.rb b/web/documentserver-example/ruby/app/models/file_model.rb
index 55e04179..f29efeb8 100755
--- a/web/documentserver-example/ruby/app/models/file_model.rb
+++ b/web/documentserver-example/ruby/app/models/file_model.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/models/file_utility.rb b/web/documentserver-example/ruby/app/models/file_utility.rb
index 204dbcac..5e7965a8 100644
--- a/web/documentserver-example/ruby/app/models/file_utility.rb
+++ b/web/documentserver-example/ruby/app/models/file_utility.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/models/jwt_helper.rb b/web/documentserver-example/ruby/app/models/jwt_helper.rb
index f97ebe80..842c89f2 100644
--- a/web/documentserver-example/ruby/app/models/jwt_helper.rb
+++ b/web/documentserver-example/ruby/app/models/jwt_helper.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/models/service_converter.rb b/web/documentserver-example/ruby/app/models/service_converter.rb
index f307c675..89717134 100755
--- a/web/documentserver-example/ruby/app/models/service_converter.rb
+++ b/web/documentserver-example/ruby/app/models/service_converter.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/models/track_helper.rb b/web/documentserver-example/ruby/app/models/track_helper.rb
index c6ef6148..aee64911 100755
--- a/web/documentserver-example/ruby/app/models/track_helper.rb
+++ b/web/documentserver-example/ruby/app/models/track_helper.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/app/models/users.rb b/web/documentserver-example/ruby/app/models/users.rb
index d2189723..6d178dcd 100644
--- a/web/documentserver-example/ruby/app/models/users.rb
+++ b/web/documentserver-example/ruby/app/models/users.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 #
 # (c) Copyright Ascensio System SIA 2023
 #
diff --git a/web/documentserver-example/ruby/config.ru b/web/documentserver-example/ruby/config.ru
index e906496b..edb2b97b 100644
--- a/web/documentserver-example/ruby/config.ru
+++ b/web/documentserver-example/ruby/config.ru
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require_relative 'config/application'
 
 Rails.application.initialize!
diff --git a/web/documentserver-example/ruby/config/application.rb b/web/documentserver-example/ruby/config/application.rb
index ae55c78c..6f8a36e1 100644
--- a/web/documentserver-example/ruby/config/application.rb
+++ b/web/documentserver-example/ruby/config/application.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require_relative 'boot'
 
 require 'active_model/railtie'
diff --git a/web/documentserver-example/ruby/config/boot.rb b/web/documentserver-example/ruby/config/boot.rb
index 5cea2ab2..3ceeeffe 100644
--- a/web/documentserver-example/ruby/config/boot.rb
+++ b/web/documentserver-example/ruby/config/boot.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
 require 'bundler/setup'