diff --git a/.rubocop.yml b/.rubocop.yml
index 1a8fe49..ef0f722 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -52,6 +52,9 @@ Style/ConditionalAssignment:
 Style/Encoding:
   Enabled: true
 
+Style/ExpandPathArguments:
+  Enabled: true
+
 Style/EmptyMethod:
   Enabled: true
 
@@ -81,3 +84,9 @@ Style/Semicolon:
 
 Style/SingleLineMethods:
   Enabled: true
+
+Style/SpecialGlobalVars:
+  Enabled: true
+
+Style/UnneededPercentQ:
+  Enabled: true
diff --git a/rack-attack.gemspec b/rack-attack.gemspec
index 7312881..d911931 100644
--- a/rack-attack.gemspec
+++ b/rack-attack.gemspec
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-lib = File.expand_path('../lib/', __FILE__)
-$:.unshift lib unless $:.include?(lib)
+lib = File.expand_path('lib', __dir__)
+$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 
 require 'rack/attack/version'
 
@@ -18,7 +18,7 @@ Gem::Specification.new do |s|
   s.homepage = 'https://github.com/kickstarter/rack-attack'
   s.rdoc_options = ["--charset=UTF-8"]
   s.require_paths = ["lib"]
-  s.summary = %q{Block & throttle abusive requests}
+  s.summary = 'Block & throttle abusive requests'
   s.test_files = Dir.glob("spec/**/*")
 
   s.metadata = {