diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 688a7aa..f9288c0 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -22,7 +22,7 @@ Other requirements:
 2) Follow the style conventions of the surrounding code. In most cases, this is standard ruby style.
 3) Add API documentation if it's a new feature
 4) Update API documentation if it changes an existing feature
-5) Bonus points for sending a PR to [github.com/dry-rb/dry-rb.org](github.com/dry-rb/dry-rb.org) which updates user documentation and guides
+5) Bonus points for sending a PR which updates user documentation in the `docsite` directory
 
 # Asking for help
 
diff --git a/Gemfile.devtools b/Gemfile.devtools
index 029d60c..3534d49 100644
--- a/Gemfile.devtools
+++ b/Gemfile.devtools
@@ -2,8 +2,6 @@
 
 git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
-gem "ossy", github: "solnic/ossy", branch: "master", platforms: :ruby
-
 group :test do
   gem 'codacy-coverage', require: false, platforms: :ruby
   gem 'simplecov', require: false, platforms: :ruby
diff --git a/spec/support/coverage.rb b/spec/support/coverage.rb
index e67e9d2..d690afd 100644
--- a/spec/support/coverage.rb
+++ b/spec/support/coverage.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # this file is managed by dry-rb/devtools
 
 if ENV['COVERAGE'] == 'true'
diff --git a/spec/support/warnings.rb b/spec/support/warnings.rb
index 6e371ab..f4ce806 100644
--- a/spec/support/warnings.rb
+++ b/spec/support/warnings.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # this file is managed by dry-rb/devtools project
 
 require 'warning'