diff --git a/.travis.yml b/.travis.yml
index a45ae24aa..f6e49fa38 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,14 +2,17 @@ language: ruby
 cache: bundler
 
 addons:
-  postgresql: '9.4'
+  postgresql: '10'
+
+services:
+  - mysql
+  - postgresql
 
 rvm:
-  - ruby-head
-  - 2.5.1
-  - 2.4.4
+  - 2.6.5
+  - 2.5.5
+  - 2.4.6
   - 2.3.7
-  - 2.2.7
 
 env:
   - DB=sqlite3
@@ -22,13 +25,10 @@ gemfile:
   - gemfiles/activerecord_5.0.gemfile
   - gemfiles/activerecord_6.0.gemfile
 
-sudo: false
-
 bundler_args: '--without local_development --jobs 3 --retry 3'
 
 before_install:
-    - gem uninstall -v '>= 2' -i $(rvm gemdir)@global -ax bundler || true
-    - gem install bundler -v '< 2'
+    - gem install bundler
 
 script: bundle exec rake
 
@@ -37,9 +37,7 @@ matrix:
     - rvm: ruby-head
   fast_finish: true
   exclude:
-    - rvm: 2.2.7
-      gemfile: gemfiles/activerecord_6.0.gemfile
     - rvm: 2.3.7
       gemfile: gemfiles/activerecord_6.0.gemfile
-    - rvm: 2.4.4
+    - rvm: 2.4.6
       gemfile: gemfiles/activerecord_6.0.gemfile
diff --git a/acts-as-taggable-on.gemspec b/acts-as-taggable-on.gemspec
index 484a0c35d..e88cbe9b8 100644
--- a/acts-as-taggable-on.gemspec
+++ b/acts-as-taggable-on.gemspec
@@ -16,7 +16,7 @@ Gem::Specification.new do |gem|
   gem.files         = `git ls-files`.split($/)
   gem.test_files    = gem.files.grep(%r{^spec/})
   gem.require_paths = ['lib']
-  gem.required_ruby_version     = '>= 2.2.7'
+  gem.required_ruby_version     = '>= 2.3.7'
 
   if File.exist?('UPGRADING.md')
     gem.post_install_message = File.read('UPGRADING.md')
diff --git a/gemfiles/activerecord_5.0.gemfile b/gemfiles/activerecord_5.0.gemfile
index e48906999..d519519f6 100644
--- a/gemfiles/activerecord_5.0.gemfile
+++ b/gemfiles/activerecord_5.0.gemfile
@@ -1,5 +1,3 @@
-# This file was generated by Appraisal
-
 source "https://rubygems.org"
 
 gem "activerecord", "~> 5.0.3"
@@ -9,7 +7,7 @@ when "postgresql"
 when "mysql"
   gem 'mysql2', '~> 0.3'
 else
-  gem 'sqlite3'
+  gem "sqlite3", "~> 1.3", "< 1.4"
 end
 
 group :local_development do
@@ -17,7 +15,7 @@ group :local_development do
   gem "guard-rspec"
   gem "appraisal"
   gem "rake"
-  gem "byebug", platforms: [:mri_21, :mri_22, :mri_23]
+  gem "byebug", platforms: [:mri]
 end
 
 gemspec path: "../"
diff --git a/gemfiles/activerecord_5.1.gemfile b/gemfiles/activerecord_5.1.gemfile
index ca8c1920c..aa0fe0587 100644
--- a/gemfiles/activerecord_5.1.gemfile
+++ b/gemfiles/activerecord_5.1.gemfile
@@ -1,5 +1,3 @@
-# This file was generated by Appraisal
-
 source "https://rubygems.org"
 
 gem "activerecord", "~> 5.1.1"
@@ -9,7 +7,7 @@ when "postgresql"
 when "mysql"
   gem 'mysql2', '~> 0.3'
 else
-  gem 'sqlite3'
+  gem "sqlite3", "~> 1.3", "< 1.4"
 end
 
 group :local_development do
@@ -17,7 +15,7 @@ group :local_development do
   gem "guard-rspec"
   gem "appraisal"
   gem "rake"
-  gem "byebug", platforms: [:mri_21, :mri_22, :mri_23]
+  gem "byebug", platforms: [:mri]
 end
 
 gemspec path: "../"
diff --git a/gemfiles/activerecord_5.2.gemfile b/gemfiles/activerecord_5.2.gemfile
index fe6525fdd..4ed6f1e6c 100644
--- a/gemfiles/activerecord_5.2.gemfile
+++ b/gemfiles/activerecord_5.2.gemfile
@@ -1,5 +1,3 @@
-# This file was generated by Appraisal
-
 source "https://rubygems.org"
 
 gem "activerecord", "~> 5.2.0"
@@ -9,7 +7,7 @@ when "postgresql"
 when "mysql"
   gem 'mysql2', '~> 0.3'
 else
-  gem 'sqlite3'
+  gem "sqlite3", "~> 1.3", "< 1.4"
 end
 
 group :local_development do
@@ -17,7 +15,7 @@ group :local_development do
   gem "guard-rspec"
   gem "appraisal"
   gem "rake"
-  gem "byebug", platforms: [:mri_21, :mri_22, :mri_23]
+  gem "byebug", platforms: [:mri]
 end
 
 gemspec path: "../"
diff --git a/gemfiles/activerecord_6.0.gemfile b/gemfiles/activerecord_6.0.gemfile
index c54c5a249..6f78ffcf9 100644
--- a/gemfiles/activerecord_6.0.gemfile
+++ b/gemfiles/activerecord_6.0.gemfile
@@ -1,8 +1,6 @@
-# This file was generated by Appraisal
-
 source "https://rubygems.org"
 
-gem "activerecord", "~> 6.0.0.beta1"
+gem "activerecord", "~> 6.0.0"
 case ENV["DB"]
 when "postgresql"
   gem 'pg'
@@ -17,7 +15,7 @@ group :local_development do
   gem "guard-rspec"
   gem "appraisal"
   gem "rake"
-  gem "byebug", platforms: [:mri_21, :mri_22, :mri_23]
+  gem "byebug", platforms: [:mri]
 end
 
 gemspec path: "../"
diff --git a/lib/acts-as-taggable-on.rb b/lib/acts-as-taggable-on.rb
index e198fa95c..3e6a6d9d3 100644
--- a/lib/acts-as-taggable-on.rb
+++ b/lib/acts-as-taggable-on.rb
@@ -31,6 +31,7 @@ module ActsAsTaggableOn
     autoload :Dirty
     autoload :Ownership
     autoload :Related
+    autoload :TagListType
   end
 
   autoload :Utils
diff --git a/lib/acts_as_taggable_on/tag.rb b/lib/acts_as_taggable_on/tag.rb
index 1cce87184..f1e0e3b3f 100644
--- a/lib/acts_as_taggable_on/tag.rb
+++ b/lib/acts_as_taggable_on/tag.rb
@@ -105,8 +105,6 @@ def count
 
     class << self
 
-
-
       private
 
       def comparable_name(str)
@@ -121,20 +119,12 @@ def binary
         ActsAsTaggableOn::Utils.using_mysql? ? 'BINARY ' : nil
       end
 
-      def unicode_downcase(string)
-        if ActiveSupport::Multibyte::Unicode.respond_to?(:downcase)
-          ActiveSupport::Multibyte::Unicode.downcase(string)
-        else
-          ActiveSupport::Multibyte::Chars.new(string).downcase.to_s
-        end
+      def as_8bit_ascii(string)
+        string.to_s.mb_chars
       end
 
-      def as_8bit_ascii(string)
-        if defined?(Encoding)
-          string.to_s.dup.force_encoding('BINARY')
-        else
-          string.to_s.mb_chars
-        end
+      def unicode_downcase(string)
+        as_8bit_ascii(string).downcase
       end
 
       def sanitize_sql_for_named_any(tag)
diff --git a/lib/acts_as_taggable_on/taggable/core.rb b/lib/acts_as_taggable_on/taggable/core.rb
index f0d88035b..83195f7d6 100644
--- a/lib/acts_as_taggable_on/taggable/core.rb
+++ b/lib/acts_as_taggable_on/taggable/core.rb
@@ -1,4 +1,5 @@
 require_relative 'tagged_with_query'
+require_relative 'tag_list_type'
 
 module ActsAsTaggableOn::Taggable
   module Core
@@ -38,7 +39,7 @@ def initialize_acts_as_taggable_on_core
                      through: context_taggings,
                      source: :tag
 
-            attribute "#{tags_type.singularize}_list".to_sym, ActiveModel::Type::Value.new
+            attribute "#{tags_type.singularize}_list".to_sym, ActsAsTaggableOn::Taggable::TagListType.new
           end
 
           taggable_mixin.class_eval <<-RUBY, __FILE__, __LINE__ + 1
@@ -49,8 +50,14 @@ def #{tag_type}_list
             def #{tag_type}_list=(new_tags)
               parsed_new_list = ActsAsTaggableOn.default_parser.new(new_tags).parse
 
-              if self.class.preserve_tag_order? || parsed_new_list.sort != #{tag_type}_list.sort
-                set_attribute_was('#{tag_type}_list', #{tag_type}_list)
+              if self.class.preserve_tag_order? || (parsed_new_list.sort != #{tag_type}_list.sort)
+                if ActsAsTaggableOn::Utils.legacy_activerecord?
+                  set_attribute_was("#{tag_type}_list", #{tag_type}_list)
+                else
+                  unless #{tag_type}_list_changed?
+                    @attributes["#{tag_type}_list"] = ActiveModel::Attribute.from_user("#{tag_type}_list", #{tag_type}_list, ActsAsTaggableOn::Taggable::TagListType.new)
+                  end
+                end
                 write_attribute("#{tag_type}_list", parsed_new_list)
               end
 
diff --git a/lib/acts_as_taggable_on/taggable/tag_list_type.rb b/lib/acts_as_taggable_on/taggable/tag_list_type.rb
new file mode 100644
index 000000000..d53a1e3dd
--- /dev/null
+++ b/lib/acts_as_taggable_on/taggable/tag_list_type.rb
@@ -0,0 +1,4 @@
+module ActsAsTaggableOn::Taggable
+  class TagListType < ActiveModel::Type::Value
+  end
+end
diff --git a/lib/acts_as_taggable_on/utils.rb b/lib/acts_as_taggable_on/utils.rb
index 3297c3a1e..c0515e7dc 100644
--- a/lib/acts_as_taggable_on/utils.rb
+++ b/lib/acts_as_taggable_on/utils.rb
@@ -24,6 +24,10 @@ def like_operator
         using_postgresql? ? 'ILIKE' : 'LIKE'
       end
 
+      def legacy_activerecord?
+        ActiveRecord.version <= Gem::Version.new('5.3.0')
+      end
+
       # escape _ and % characters in strings, since these are wildcards in SQL.
       def escape_like(str)
         str.gsub(/[!%_]/) { |x| '!' + x }
diff --git a/lib/acts_as_taggable_on/version.rb b/lib/acts_as_taggable_on/version.rb
index 117bd0615..7a08a2a78 100644
--- a/lib/acts_as_taggable_on/version.rb
+++ b/lib/acts_as_taggable_on/version.rb
@@ -1,3 +1,3 @@
 module ActsAsTaggableOn
-  VERSION = '6.0.1'
+  VERSION = '6.5.0'
 end
diff --git a/spec/acts_as_taggable_on/acts_as_taggable_on_spec.rb b/spec/acts_as_taggable_on/acts_as_taggable_on_spec.rb
index 7ab80cbe6..52e59c180 100644
--- a/spec/acts_as_taggable_on/acts_as_taggable_on_spec.rb
+++ b/spec/acts_as_taggable_on/acts_as_taggable_on_spec.rb
@@ -192,7 +192,7 @@
       its(:cached_glass_list)    { should be_blank }
 
       context 'language taggings cache after update' do
-        before  { @taggable.update_attributes(language_list: 'ruby, .net') }
+        before  { @taggable.update(language_list: 'ruby, .net') }
         subject { @taggable }
 
         its(:language_list)        { should == ['ruby', '.net']}
@@ -201,7 +201,7 @@
       end
 
       context 'status taggings cache after update' do
-        before  { @taggable.update_attributes(status_list: 'happy, married') }
+        before  { @taggable.update(status_list: 'happy, married') }
         subject { @taggable }
 
         its(:status_list)        { should     == ['happy', 'married'] }
@@ -214,7 +214,7 @@
 
       context 'glass taggings cache after update' do
         before do
-          @taggable.update_attributes(glass_list: 'rectangle, aviator')
+          @taggable.update(glass_list: 'rectangle, aviator')
         end
 
         subject { @taggable }
diff --git a/spec/acts_as_taggable_on/caching_spec.rb b/spec/acts_as_taggable_on/caching_spec.rb
index 9391fe96b..8db1b7884 100644
--- a/spec/acts_as_taggable_on/caching_spec.rb
+++ b/spec/acts_as_taggable_on/caching_spec.rb
@@ -31,40 +31,40 @@
     end
 
     it 'should cache tags' do
-      @taggable.update_attributes(tag_list: 'awesome, epic')
+      @taggable.update(tag_list: 'awesome, epic')
       expect(@taggable.cached_tag_list).to eq('awesome, epic')
 
-      @another_taggable.update_attributes(language_list: 'ruby, .net')
+      @another_taggable.update(language_list: 'ruby, .net')
       expect(@another_taggable.cached_language_list).to eq('ruby, .net')
     end
 
     it 'should keep the cache' do
-      @taggable.update_attributes(tag_list: 'awesome, epic')
+      @taggable.update(tag_list: 'awesome, epic')
       @taggable = CachedModel.find(@taggable.id)
       @taggable.save!
       expect(@taggable.cached_tag_list).to eq('awesome, epic')
     end
 
     it 'should update the cache' do
-      @taggable.update_attributes(tag_list: 'awesome, epic')
-      @taggable.update_attributes(tag_list: 'awesome')
+      @taggable.update(tag_list: 'awesome, epic')
+      @taggable.update(tag_list: 'awesome')
       expect(@taggable.cached_tag_list).to eq('awesome')
     end
 
     it 'should remove the cache' do
-      @taggable.update_attributes(tag_list: 'awesome, epic')
-      @taggable.update_attributes(tag_list: '')
+      @taggable.update(tag_list: 'awesome, epic')
+      @taggable.update(tag_list: '')
       expect(@taggable.cached_tag_list).to be_blank
     end
 
     it 'should have a tag list' do
-      @taggable.update_attributes(tag_list: 'awesome, epic')
+      @taggable.update(tag_list: 'awesome, epic')
       @taggable = CachedModel.find(@taggable.id)
       expect(@taggable.tag_list.sort).to eq(%w(awesome epic).sort)
     end
 
     it 'should keep the tag list' do
-      @taggable.update_attributes(tag_list: 'awesome, epic')
+      @taggable.update(tag_list: 'awesome, epic')
       @taggable = CachedModel.find(@taggable.id)
       @taggable.save!
       expect(@taggable.tag_list.sort).to eq(%w(awesome epic).sort)
@@ -95,7 +95,7 @@
     end
 
     it 'should cache tags with custom delimiter' do
-      @taggable.update_attributes(tag_list: 'awesome; epic')
+      @taggable.update(tag_list: 'awesome; epic')
       expect(@taggable.tag_list).to eq(['awesome', 'epic'])
       expect(@taggable.cached_tag_list).to eq('awesome; epic')
 
diff --git a/spec/acts_as_taggable_on/single_table_inheritance_spec.rb b/spec/acts_as_taggable_on/single_table_inheritance_spec.rb
index 22ea2adb2..ef1f8d100 100644
--- a/spec/acts_as_taggable_on/single_table_inheritance_spec.rb
+++ b/spec/acts_as_taggable_on/single_table_inheritance_spec.rb
@@ -150,7 +150,7 @@
       inheriting_model.tag_list = 'one'
       inheriting_model.save!
 
-      inheriting_model.update_attributes! name: 'foo'
+      inheriting_model.update! name: 'foo'
     end
 
     it "should only join with taggable's table to check type for inherited models" do
diff --git a/spec/acts_as_taggable_on/taggable_spec.rb b/spec/acts_as_taggable_on/taggable_spec.rb
index a6c07cf92..f91f79aba 100644
--- a/spec/acts_as_taggable_on/taggable_spec.rb
+++ b/spec/acts_as_taggable_on/taggable_spec.rb
@@ -541,7 +541,7 @@
 
   it 'should not delete tags if not updated' do
     model = TaggableModel.create(name: 'foo', tag_list: 'ruby, rails, programming')
-    model.update_attributes(name: 'bar')
+    model.update(name: 'bar')
     model.reload
     expect(model.tag_list.sort).to eq(%w(ruby rails programming).sort)
   end
diff --git a/spec/acts_as_taggable_on/tagger_spec.rb b/spec/acts_as_taggable_on/tagger_spec.rb
index 174af1226..4ed31f273 100644
--- a/spec/acts_as_taggable_on/tagger_spec.rb
+++ b/spec/acts_as_taggable_on/tagger_spec.rb
@@ -112,7 +112,7 @@
   end
 
   it 'should not lose tags' do
-    @taggable.update_attributes(tag_list: 'ruby')
+    @taggable.update(tag_list: 'ruby')
     @user.tag(@taggable, with: 'ruby, scheme', on: :tags)
 
     [@taggable, @user].each(&:reload)
@@ -120,7 +120,7 @@
     expect(@taggable.all_tags_list.sort).to eq(%w(ruby scheme).sort)
 
     expect(-> {
-      @taggable.update_attributes(tag_list: '')
+      @taggable.update(tag_list: '')
     }).to change(ActsAsTaggableOn::Tagging, :count).by(-1)
 
     expect(@taggable.tag_list).to be_empty