diff --git a/.hound.yml b/.hound.yml
index 0b423860b..c7c92dcfe 100644
--- a/.hound.yml
+++ b/.hound.yml
@@ -1,6 +1,6 @@
 rubocop:
   config_file: .rubocop.yml
-  version: 0.83.0
+  version: 0.91.0
 scss:
   config_file: .scss-lint.yml
 erblint:
diff --git a/.rubocop.yml b/.rubocop.yml
index 9941c7659..b74689518 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -15,6 +15,7 @@ Bundler/DuplicatedGem:
 
 Bundler/OrderedGems:
   Enabled: true
+  ConsiderPunctuation: true
 
 Capybara/CurrentPathExpectation:
   Enabled: true
@@ -165,9 +166,15 @@ Layout/TrailingWhitespace:
 Lint/AmbiguousRegexpLiteral:
   Enabled: true
 
+Lint/ConstantDefinitionInBlock:
+  Enabled: true
+
 Lint/DuplicateMethods:
   Enabled: true
 
+Lint/EmptyFile:
+  Enabled: true
+
 Lint/LiteralAsCondition:
   Enabled: true
 
@@ -367,9 +374,15 @@ Security/JSONLoad:
 Security/YAMLLoad:
   Enabled: true
 
+Style/AccessorGrouping:
+  Enabled: true
+
 Style/AndOr:
   Enabled: true
 
+Style/ArrayCoercion:
+  Enabled: true
+
 Style/BlockDelimiters:
   Enabled: true
 
@@ -406,6 +419,9 @@ Style/PercentLiteralDelimiters:
 Style/Proc:
   Enabled: true
 
+Style/RedundantFileExtensionInRequire:
+  Enabled: true
+
 Style/RedundantFreeze:
   Enabled: true
 
diff --git a/Gemfile b/Gemfile
index f5580c981..6a3827b69 100644
--- a/Gemfile
+++ b/Gemfile
@@ -102,7 +102,7 @@ group :development do
   gem "erb_lint", require: false
   gem "github_changelog_generator", "~> 1.15.2"
   gem "mdl", "~> 0.11.0", require: false
-  gem "rubocop", "~> 0.83.0", require: false
+  gem "rubocop", "~> 0.91.0", require: false
   gem "rubocop-performance", "~> 1.7.1", require: false
   gem "rubocop-rails", "~> 2.3.2", require: false
   gem "rubocop-rspec", "~> 1.35.0", require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 35285d5f1..883830f58 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -493,13 +493,17 @@ GEM
       rspec-mocks (~> 3.9)
       rspec-support (~> 3.9)
     rspec-support (3.9.3)
-    rubocop (0.83.0)
+    rubocop (0.91.1)
       parallel (~> 1.10)
-      parser (>= 2.7.0.1)
+      parser (>= 2.7.1.1)
       rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 1.7)
       rexml
+      rubocop-ast (>= 0.4.0, < 1.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (>= 1.4.0, < 2.0)
+    rubocop-ast (0.7.1)
+      parser (>= 2.7.1.5)
     rubocop-performance (1.7.1)
       rubocop (>= 0.82.0)
     rubocop-rails (2.3.2)
@@ -707,7 +711,7 @@ DEPENDENCIES
   rinku (~> 2.0.6)
   rollbar (~> 3.0.0)
   rspec-rails (~> 4.0)
-  rubocop (~> 0.83.0)
+  rubocop (~> 0.91.0)
   rubocop-performance (~> 1.7.1)
   rubocop-rails (~> 2.3.2)
   rubocop-rspec (~> 1.35.0)
diff --git a/app/controllers/concerns/translatable.rb b/app/controllers/concerns/translatable.rb
index 533b8db22..8bff3b08d 100644
--- a/app/controllers/concerns/translatable.rb
+++ b/app/controllers/concerns/translatable.rb
@@ -6,10 +6,10 @@ module Translatable
     def translation_params(resource_model, options = {})
       attributes = [:id, :locale, :_destroy]
       if options[:only]
-        attributes += [*options[:only]]
+        attributes += Array(options[:only])
       else
         attributes += resource_model.translated_attribute_names
       end
-      { translations_attributes: attributes - [*options[:except]] }
+      { translations_attributes: attributes - Array(options[:except]) }
     end
 end
diff --git a/app/helpers/followables_helper.rb b/app/helpers/followables_helper.rb
index ee01d9aee..52a90f156 100644
--- a/app/helpers/followables_helper.rb
+++ b/app/helpers/followables_helper.rb
@@ -14,7 +14,7 @@ module FollowablesHelper
     return unless follow.followable.present?
 
     followable = follow.followable
-    partial = followable_class_name(followable) + "_follow"
+    partial = "#{followable_class_name(followable)}_follow"
     locals = { followable_class_name(followable).to_sym => followable }
 
     render partial, locals
diff --git a/app/helpers/tracks_helper.rb b/app/helpers/tracks_helper.rb
index 305876915..8236751d5 100644
--- a/app/helpers/tracks_helper.rb
+++ b/app/helpers/tracks_helper.rb
@@ -3,7 +3,7 @@ module TracksHelper
     track_data = ""
     prefix = " data-track-event-"
     data.each do |key, value|
-      track_data = track_data + prefix + key.to_s + "=" + value + " "
+      track_data = "#{track_data}#{prefix}#{key}=#{value} "
     end
     content_for :track_event do
       track_data
diff --git a/app/helpers/verification_helper.rb b/app/helpers/verification_helper.rb
index 587e17859..3dd9123c9 100644
--- a/app/helpers/verification_helper.rb
+++ b/app/helpers/verification_helper.rb
@@ -21,6 +21,6 @@ module VerificationHelper
     data_to_mask    = match[2]
     email_provider  = match[3]
 
-    data_to_display + "*" * data_to_mask.size + "@" + email_provider
+    "#{data_to_display}#{"*" * data_to_mask.size}@#{email_provider}"
   end
 end
diff --git a/app/helpers/votes_helper.rb b/app/helpers/votes_helper.rb
index dd436ea4e..8739c2323 100644
--- a/app/helpers/votes_helper.rb
+++ b/app/helpers/votes_helper.rb
@@ -7,9 +7,9 @@ module VotesHelper
     return "0%" if debate.total_votes == 0
 
     if vote == "likes"
-      debate_percentage_of_likes(debate).to_s + "%"
+      "#{debate_percentage_of_likes(debate)}%"
     elsif vote == "dislikes"
-      (100 - debate_percentage_of_likes(debate)).to_s + "%"
+      "#{100 - debate_percentage_of_likes(debate)}%"
     end
   end
 
diff --git a/app/models/user.rb b/app/models/user.rb
index ac530d3a1..5daabdb50 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -89,9 +89,7 @@ class User < ApplicationRecord
 
   accepts_nested_attributes_for :organization, update_only: true
 
-  attr_accessor :skip_password_validation
-  attr_accessor :use_redeemable_code
-  attr_accessor :login
+  attr_accessor :skip_password_validation, :use_redeemable_code, :login
 
   scope :administrators, -> { joins(:administrator) }
   scope :moderators,     -> { joins(:moderator) }
diff --git a/app/models/verification/management/email.rb b/app/models/verification/management/email.rb
index ed76e74d8..5348c97ba 100644
--- a/app/models/verification/management/email.rb
+++ b/app/models/verification/management/email.rb
@@ -1,9 +1,7 @@
 class Verification::Management::Email
   include ActiveModel::Model
 
-  attr_accessor :document_type
-  attr_accessor :document_number
-  attr_accessor :email
+  attr_accessor :document_type, :document_number, :email
 
   validates :document_type, :document_number, :email, presence: true
   validates :email, format: { with: Devise.email_regexp }, allow_blank: true
diff --git a/config/application.rb b/config/application.rb
index 935dffa93..e151e7cbd 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -129,4 +129,4 @@ class Rails::Engine
   end
 end
 
-require "./config/application_custom.rb"
+require "./config/application_custom"
diff --git a/db/dev_seeds/admin_notifications.rb b/db/dev_seeds/admin_notifications.rb
index 308928d53..8823407df 100644
--- a/db/dev_seeds/admin_notifications.rb
+++ b/db/dev_seeds/admin_notifications.rb
@@ -7,7 +7,7 @@ section "Creating Admin Notifications & Templates" do
              "people will discuss & support it.",
     body_es: "Recuerda que puedes crear propuestas y los ciudadanos las debatirán y apoyarán.",
 
-    link: Setting["url"] + "/proposals",
+    link: "#{Setting["url"]}/proposals",
     segment_recipient: "administrators"
   ).deliver
 
diff --git a/db/dev_seeds/users.rb b/db/dev_seeds/users.rb
index 954f53282..a8b5ee429 100644
--- a/db/dev_seeds/users.rb
+++ b/db/dev_seeds/users.rb
@@ -17,7 +17,7 @@ section "Creating Users" do
   def unique_document_number
     @document_number ||= 12345678
     @document_number += 1
-    "#{@document_number}#{[*"A".."Z"].sample}"
+    "#{@document_number}#{("A".."Z").to_a.sample}"
   end
 
   admin = create_user("admin@consul.dev", "admin")
diff --git a/spec/controllers/concerns/has_filters_spec.rb b/spec/controllers/concerns/has_filters_spec.rb
index f4cade052..c95531265 100644
--- a/spec/controllers/concerns/has_filters_spec.rb
+++ b/spec/controllers/concerns/has_filters_spec.rb
@@ -1,9 +1,7 @@
 require "rails_helper"
 
 describe HasFilters do
-  class FakeController < ActionController::Base; end
-
-  controller(FakeController) do
+  controller(ActionController::Base) do
     include HasFilters
     has_filters ["all", "pending", "reviewed"], only: :index
 
diff --git a/spec/controllers/concerns/has_orders_spec.rb b/spec/controllers/concerns/has_orders_spec.rb
index f37b7c59a..4248e5cd5 100644
--- a/spec/controllers/concerns/has_orders_spec.rb
+++ b/spec/controllers/concerns/has_orders_spec.rb
@@ -1,9 +1,7 @@
 require "rails_helper"
 
 describe HasOrders do
-  class FakeController < ActionController::Base; end
-
-  controller(FakeController) do
+  controller(ActionController::Base) do
     include HasOrders
     has_orders ["created_at", "votes_count", "flags_count", "relevance"], only: :index
     has_orders ->(c) { ["votes_count", "flags_count"] }, only: :new
diff --git a/spec/controllers/welcome_controller_spec.rb b/spec/controllers/welcome_controller_spec.rb
deleted file mode 100644
index e69de29bb..000000000
diff --git a/spec/lib/consul_form_builder_spec.rb b/spec/lib/consul_form_builder_spec.rb
index 91d22ab89..ed73b6b62 100644
--- a/spec/lib/consul_form_builder_spec.rb
+++ b/spec/lib/consul_form_builder_spec.rb
@@ -1,10 +1,14 @@
 require "rails_helper"
 
 describe ConsulFormBuilder do
-  class DummyModel
-    include ActiveModel::Model
-    OPTIONS = %w[Good Bad Ugly].freeze
-    attr_accessor :title, :quality
+  before do
+    dummy_model = Class.new do
+      include ActiveModel::Model
+      attr_accessor :title, :quality
+    end
+
+    stub_const("DummyModel", dummy_model)
+    stub_const("DummyModel::OPTIONS", %w[Good Bad Ugly].freeze)
   end
 
   let(:builder) { ConsulFormBuilder.new(:dummy, DummyModel.new, ActionView::Base.new, {}) }
diff --git a/spec/models/statisticable_spec.rb b/spec/models/statisticable_spec.rb
index 3757d3db8..1cc57ca2a 100644
--- a/spec/models/statisticable_spec.rb
+++ b/spec/models/statisticable_spec.rb
@@ -1,12 +1,16 @@
 require "rails_helper"
 
 describe Statisticable do
-  class DummyStats
-    include Statisticable
+  before do
+    dummy_stats = Class.new do
+      include Statisticable
 
-    def participants
-      User.all
+      def participants
+        User.all
+      end
     end
+
+    stub_const("DummyStats", dummy_stats)
   end
 
   let(:stats) { DummyStats.new(nil) }
diff --git a/spec/shared/system/nested_documentable.rb b/spec/shared/system/nested_documentable.rb
index 9c6482d84..a44096f06 100644
--- a/spec/shared/system/nested_documentable.rb
+++ b/spec/shared/system/nested_documentable.rb
@@ -235,12 +235,11 @@ shared_examples "nested documentable" do |login_as_name, documentable_factory_na
       end
       login_as user_to_login
       visit send(path, arguments)
-      FILENAMES ||= %w[clippy empty logo].freeze
 
       send(fill_resource_method_name) if fill_resource_method_name
 
-      documentable.class.max_documents_allowed.times.zip(FILENAMES).each do |_n, fn|
-        documentable_attach_new_file(Rails.root.join("spec/fixtures/files/#{fn}.pdf"))
+      %w[clippy empty logo].take(documentable.class.max_documents_allowed).each do |filename|
+        documentable_attach_new_file(Rails.root.join("spec/fixtures/files/#{filename}.pdf"))
       end
 
       click_on submit_button
diff --git a/spec/system/admin/homepage/homepage_spec.rb b/spec/system/admin/homepage/homepage_spec.rb
index e2ba36f7a..9a44cda7d 100644
--- a/spec/system/admin/homepage/homepage_spec.rb
+++ b/spec/system/admin/homepage/homepage_spec.rb
@@ -22,7 +22,7 @@ describe "Homepage" do
     scenario "Admin menu links to homepage path" do
       visit new_admin_widget_card_path(header_card: true)
 
-      click_link Setting["org_name"] + " Administration"
+      click_link "#{Setting["org_name"]} Administration"
 
       expect(page).to have_current_path(admin_root_path)
     end
diff --git a/spec/system/admin/site_customization/documents_spec.rb b/spec/system/admin/site_customization/documents_spec.rb
index 1b0ac771b..51d0a3f2b 100644
--- a/spec/system/admin/site_customization/documents_spec.rb
+++ b/spec/system/admin/site_customization/documents_spec.rb
@@ -58,7 +58,7 @@ describe "Documents" do
   scenario "Create" do
     visit new_admin_site_customization_document_path
 
-    attach_file("document_attachment", Rails.root + "spec/fixtures/files/logo.pdf")
+    attach_file("document_attachment", "#{Rails.root}/spec/fixtures/files/logo.pdf")
     click_button "Upload"
 
     expect(page).to have_content "Document uploaded succesfully"
diff --git a/spec/system/social_media_meta_tags_spec.rb b/spec/system/social_media_meta_tags_spec.rb
index f114c204f..448776b9d 100644
--- a/spec/system/social_media_meta_tags_spec.rb
+++ b/spec/system/social_media_meta_tags_spec.rb
@@ -33,8 +33,7 @@ describe "Social media meta tags" do
 
       expect(page).to have_property "og:title", with: meta_title
       expect(page).to have_property "article:publisher", with: url
-      expect(page).to have_property "article:author", with: "https://www.facebook.com/" +
-                                                             facebook_handle
+      expect(page).to have_property "article:author", with: "https://www.facebook.com/#{facebook_handle}"
       expect(page).to have_property "og:url", with: "#{Capybara.app_host}/"
       expect(page).to have_property "og:image", with: "#{Capybara.app_host}/social_media_icon.png"
       expect(page).to have_property "og:site_name", with: org_name
diff --git a/spec/views/shared/errors_spec.rb b/spec/views/shared/errors_spec.rb
index 6e3c4ec49..1159f58c7 100644
--- a/spec/views/shared/errors_spec.rb
+++ b/spec/views/shared/errors_spec.rb
@@ -1,13 +1,17 @@
 require "rails_helper"
 
 describe "shared errors" do
-  class DummyModel
-    include ActiveModel::Model
-    attr_accessor :title, :description, :days
+  before do
+    dummy_model = Class.new do
+      include ActiveModel::Model
+      attr_accessor :title, :description, :days
 
-    validates :title, presence: true
-    validates :description, presence: true, length: { in: 10..100 }
-    validates :days, numericality: { greater_than: 10 }
+      validates :title, presence: true
+      validates :description, presence: true, length: { in: 10..100 }
+      validates :days, numericality: { greater_than: 10 }
+    end
+
+    stub_const("DummyModel", dummy_model)
   end
 
   it "counts the number of fields with errors" do