diff --git a/.rubocop.yml b/.rubocop.yml
index d4cfc33b..f08a887c 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,5 @@
 AllCops:
-  Includes:
+  Include:
     - 'Gemfile'
     - 'Rakefile'
     - 'http.gemspec'
@@ -99,3 +99,18 @@ PercentLiteralDelimiters:
 Semicolon:
   Exclude:
     - 'spec/support/'
+
+# Do not force first argument to be separated with exactly single space.
+# My (ixti) personal preference is to align code in columns when it makes
+# sense:
+#
+#   module HTTP
+#     module MimeType
+#       class JSON < Adapter
+#         register_adapter 'application/json', JSON
+#         register_alias   'application/json', :json
+#       end
+#     end
+#   end
+SingleSpaceBeforeFirstArg:
+  Enabled: false
diff --git a/Gemfile b/Gemfile
index 5ccd6995..223a6807 100644
--- a/Gemfile
+++ b/Gemfile
@@ -21,7 +21,7 @@ group :test do
   gem 'json', '>= 1.8.1', :platforms => [:jruby, :rbx, :ruby_18, :ruby_19]
   gem 'mime-types', '~> 1.25', :platforms => [:jruby, :ruby_18]
   gem 'rspec', '>= 2.14'
-  gem 'rubocop', '~> 0.19.0', :platforms => [:ruby_19, :ruby_20, :ruby_21]
+  gem 'rubocop', '~> 0.22.0', :platforms => [:ruby_19, :ruby_20, :ruby_21]
   gem 'simplecov', :require => false
   gem 'yardstick'
 end
diff --git a/lib/http/backports/uri.rb b/lib/http/backports/uri.rb
index 28008fe4..9fca0441 100644
--- a/lib/http/backports/uri.rb
+++ b/lib/http/backports/uri.rb
@@ -81,11 +81,11 @@ def self.encode_www_form(enum)
         encode_www_form_component(k)
       elsif v.respond_to?(:to_ary)
         v.to_ary.map do |w|
+          next unless w
+
           str = encode_www_form_component(k)
-          unless w.nil?
-            str << '='
-            str << encode_www_form_component(w)
-          end
+          str << '='
+          str << encode_www_form_component(w)
         end.join('&')
       else
         str = encode_www_form_component(k)
diff --git a/lib/http/request.rb b/lib/http/request.rb
index 4059b2f2..b021f222 100644
--- a/lib/http/request.rb
+++ b/lib/http/request.rb
@@ -48,7 +48,7 @@ class UnsupportedSchemeError < RequestError; end
 
     # The following method may be removed in two minor versions (0.7.0) or one
     # major version (1.0.0)
-    def method(*args)
+    def method(*)
       warn "#{Kernel.caller.first}: [DEPRECATION] HTTP::Request#method is deprecated. Use #verb instead. For Object#method, use #__method__."
       @verb
     end
diff --git a/lib/http/response/parser.rb b/lib/http/response/parser.rb
index 44ecd347..67c3ec19 100644
--- a/lib/http/response/parser.rb
+++ b/lib/http/response/parser.rb
@@ -42,10 +42,8 @@ def on_body(chunk)
       end
 
       def chunk
-        if (chunk = @chunk)
-          @chunk = nil
-          chunk
-        end
+        chunk, @chunk = @chunk, nil
+        chunk
       end
 
       def on_message_complete
diff --git a/spec/http/client_spec.rb b/spec/http/client_spec.rb
index 36583f2d..814e8338 100644
--- a/spec/http/client_spec.rb
+++ b/spec/http/client_spec.rb
@@ -133,7 +133,7 @@ def simple_response(body, status = 200)
       let(:client)  { described_class.new :headers => headers }
 
       it 'keeps `Host` header as is' do
-        expect(client).to receive(:perform) do |req, options|
+        expect(client).to receive(:perform) do |req, _|
           expect(req['Host']).to eq 'another.example.com'
         end
 
diff --git a/spec/support/example_server.rb b/spec/support/example_server.rb
index 3483ecc7..77b4d964 100644
--- a/spec/support/example_server.rb
+++ b/spec/support/example_server.rb
@@ -41,18 +41,19 @@ def handle_root(request, response)
   end
 
   def handle_params(request, response)
-    if request.query_string == 'foo=bar'
-      response.status = 200
-      response.body     = 'Params!'
-    end
+    return unless request.query_string == 'foo=bar'
+
+    response.status = 200
+    response.body   = 'Params!'
   end
 
   def handle_multiple_params(request, response)
     params = CGI.parse(request.query_string)
-    if params == {'foo' => ['bar'], 'baz' => ['quux']}
-      response.status = 200
-      response.body     = 'More Params!'
-    end
+
+    return unless params == {'foo' => ['bar'], 'baz' => ['quux']}
+
+    response.status = 200
+    response.body   = 'More Params!'
   end
 
   def do_POST(request, response) # rubocop:disable MethodName
diff --git a/spec/support/proxy_server.rb b/spec/support/proxy_server.rb
index d4c31d13..d9909264 100644
--- a/spec/support/proxy_server.rb
+++ b/spec/support/proxy_server.rb
@@ -1,8 +1,6 @@
 require 'webrick/httpproxy'
 
-handler = proc do | req, res |
-  res['X-PROXIED'] = true
-end
+handler = proc { |_, res| res['X-PROXIED'] = true }
 
 ProxyServer = WEBrick::HTTPProxyServer.new(
   :Port => 8080,