diff --git a/.travis.yml b/.travis.yml
index eff072637..2dbf8ca12 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,7 +13,6 @@ env:
   - DB=postgresql
 
 gemfile:
-  - gemfiles/activerecord_3.2.gemfile
   - gemfiles/activerecord_4.0.gemfile
   - gemfiles/activerecord_4.1.gemfile
 
@@ -28,9 +27,3 @@ matrix:
   allow_failures:
       - gemfile: gemfiles/activerecord_edge.gemfile
       - rvm: rbx-2
-  exclude:
-      - rvm: 2.2
-        gemfile: gemfiles/activerecord_3.2.gemfile
-      - rvm: rbx-2
-        gemfile: gemfiles/activerecord_3.2.gemfile
-
diff --git a/Appraisals b/Appraisals
index c1a495a04..0e9c5e6c6 100644
--- a/Appraisals
+++ b/Appraisals
@@ -1,7 +1,3 @@
-appraise "activerecord-3.2" do
-  gem "activerecord", github: "rails/rails" , branch: '3-2-stable'
-end
-
 appraise "activerecord-4.0" do
   gem "activerecord", github: "rails/rails" , branch: '4-0-stable'
 end
diff --git a/acts-as-taggable-on.gemspec b/acts-as-taggable-on.gemspec
index 9290a8deb..21f26c2e1 100644
--- a/acts-as-taggable-on.gemspec
+++ b/acts-as-taggable-on.gemspec
@@ -22,7 +22,7 @@ Gem::Specification.new do |gem|
     gem.post_install_message = File.read('UPGRADING.md')
   end
 
-  gem.add_runtime_dependency 'activerecord', ['>= 3.2', '< 5']
+  gem.add_runtime_dependency 'activerecord', ['>= 4.0', '< 5']
 
   gem.add_development_dependency 'sqlite3'
   gem.add_development_dependency 'mysql2', '~> 0.3.7'
diff --git a/gemfiles/activerecord_3.2.gemfile b/gemfiles/activerecord_3.2.gemfile
deleted file mode 100644
index a61e18a1a..000000000
--- a/gemfiles/activerecord_3.2.gemfile
+++ /dev/null
@@ -1,15 +0,0 @@
-# This file was generated by Appraisal
-
-source "https://rubygems.org"
-
-gem "activerecord", :github => "rails/rails", :branch => "3-2-stable"
-
-group :local_development do
-  gem "guard"
-  gem "guard-rspec"
-  gem "appraisal"
-  gem "rake"
-  gem "byebug", :platform => :mri_21
-end
-
-gemspec :path => "../"
diff --git a/lib/acts-as-taggable-on.rb b/lib/acts-as-taggable-on.rb
index ad3791103..438449bf5 100644
--- a/lib/acts-as-taggable-on.rb
+++ b/lib/acts-as-taggable-on.rb
@@ -117,7 +117,6 @@ def self.apply_binary_collation(bincoll)
 end
 
 ActiveSupport.on_load(:active_record) do
-  extend ActsAsTaggableOn::Compatibility
   extend ActsAsTaggableOn::Taggable
   include ActsAsTaggableOn::Tagger
 end
diff --git a/lib/acts_as_taggable_on/compatibility.rb b/lib/acts_as_taggable_on/compatibility.rb
deleted file mode 100644
index 99e69cff9..000000000
--- a/lib/acts_as_taggable_on/compatibility.rb
+++ /dev/null
@@ -1,35 +0,0 @@
-module ActsAsTaggableOn::Compatibility
-  def has_many_with_taggable_compatibility(name, options = {}, &extention)
-    if ActsAsTaggableOn::Utils.active_record4? || ActsAsTaggableOn::Utils.active_record5?
-      scope, opts = build_taggable_scope_and_options(options)
-      has_many(name, scope, opts, &extention)
-    else
-      has_many(name, options, &extention)
-    end
-  end
-
-  def build_taggable_scope_and_options(opts)
-    scope_opts, opts = parse_taggable_options(opts)
-
-    unless scope_opts.empty?
-      scope = -> {
-        scope_opts.inject(self) { |result, hash| result.send(*hash) }
-      }
-      return [scope, opts]
-    end
-
-    [nil, opts]
-  end
-
-  def parse_taggable_options(opts)
-    scope_opts = {}
-    [:order, :having, :select, :group, :limit, :offset, :readonly].each do |o|
-      scope_opts[o] = opts.delete o if opts[o]
-    end
-    scope_opts[:where] = opts.delete :conditions if opts[:conditions]
-    scope_opts[:joins] = opts.delete :include if opts [:include]
-    scope_opts[:distinct] = opts.delete :uniq if opts[:uniq]
-
-    [scope_opts, opts]
-  end
-end
diff --git a/lib/acts_as_taggable_on/taggable/core.rb b/lib/acts_as_taggable_on/taggable/core.rb
index 963037311..2f137bb03 100644
--- a/lib/acts_as_taggable_on/taggable/core.rb
+++ b/lib/acts_as_taggable_on/taggable/core.rb
@@ -23,18 +23,15 @@ def initialize_acts_as_taggable_on_core
           class_eval do
             # when preserving tag order, include order option so that for a 'tags' context
             # the associations tag_taggings & tags are always returned in created order
-            has_many_with_taggable_compatibility context_taggings, as: :taggable,
-                                                 dependent: :destroy,
-                                                 class_name: 'ActsAsTaggableOn::Tagging',
-                                                 order: taggings_order,
-                                                 conditions: {context: tags_type},
-                                                 include: :tag
-
-            has_many_with_taggable_compatibility context_tags, through: context_taggings,
-                                                 source: :tag,
-                                                 class_name: 'ActsAsTaggableOn::Tag',
-                                                 order: taggings_order
-
+            has_many context_taggings, -> { includes(:tag).order(taggings_order).where(context: tags_type) },
+                     as: :taggable,
+                     class_name: ActsAsTaggableOn::Tagging,
+                     dependent: :destroy
+
+            has_many context_tags, -> { order(taggings_order) },
+                     class_name: ActsAsTaggableOn::Tag,
+                     through: context_taggings,
+                     source: :tag
           end
 
           taggable_mixin.class_eval <<-RUBY, __FILE__, __LINE__ + 1
diff --git a/lib/acts_as_taggable_on/tagger.rb b/lib/acts_as_taggable_on/tagger.rb
index 5c451be8f..a1ade9369 100644
--- a/lib/acts_as_taggable_on/tagger.rb
+++ b/lib/acts_as_taggable_on/tagger.rb
@@ -15,18 +15,19 @@ module ClassMethods
       #   end
       def acts_as_tagger(opts={})
         class_eval do
-          has_many_with_taggable_compatibility :owned_taggings,
-                                               opts.merge(
-                                                   as: :tagger,
-                                                   dependent: :destroy,
-                                                   class_name: '::ActsAsTaggableOn::Tagging'
-                                               )
+          owned_taggings_scope = opts.delete(:scope)
 
-          has_many_with_taggable_compatibility :owned_tags,
-                                               through: :owned_taggings,
-                                               source: :tag,
-                                               class_name: '::ActsAsTaggableOn::Tag',
-                                               uniq: true
+          has_many :owned_taggings, owned_taggings_scope,
+                   opts.merge(
+                     as: :tagger,
+                     class_name: ::ActsAsTaggableOn::Tagging,
+                     dependent: :destroy
+                   )
+
+          has_many :owned_tags, -> { distinct },
+                   class_name: ::ActsAsTaggableOn::Tag,
+                   source: :tag,
+                   through: :owned_taggings
         end
 
         include ActsAsTaggableOn::Tagger::InstanceMethods
diff --git a/lib/acts_as_taggable_on/tagging.rb b/lib/acts_as_taggable_on/tagging.rb
index df23df4ce..3411ed0cf 100644
--- a/lib/acts_as_taggable_on/tagging.rb
+++ b/lib/acts_as_taggable_on/tagging.rb
@@ -1,16 +1,5 @@
 module ActsAsTaggableOn
   class Tagging < ::ActiveRecord::Base #:nodoc:
-    #TODO, remove from 4.0.0
-    attr_accessible :tag,
-                    :tag_id,
-                    :context,
-                    :taggable,
-                    :taggable_type,
-                    :taggable_id,
-                    :tagger,
-                    :tagger_type,
-                    :tagger_id if defined?(ActiveModel::MassAssignmentSecurity)
-
     belongs_to :tag, class_name: '::ActsAsTaggableOn::Tag', counter_cache: ActsAsTaggableOn.tags_counter
     belongs_to :taggable, polymorphic: true
     belongs_to :tagger,   polymorphic: true
diff --git a/spec/acts_as_taggable_on/taggable_spec.rb b/spec/acts_as_taggable_on/taggable_spec.rb
index 97283eb7a..57e65a0a2 100644
--- a/spec/acts_as_taggable_on/taggable_spec.rb
+++ b/spec/acts_as_taggable_on/taggable_spec.rb
@@ -745,7 +745,6 @@
 
     context 'Model.limit(x).tag_counts.sum(:tags_count)' do
       it 'should not break on Mysql' do
-        # Activerecord 3.2 return a string
         expect(TaggableModel.limit(2).tag_counts.sum('tags_count').to_i).to eq(5)
       end
     end
diff --git a/spec/support/database.rb b/spec/support/database.rb
index b552645a0..8af7025ae 100644
--- a/spec/support/database.rb
+++ b/spec/support/database.rb
@@ -13,13 +13,7 @@
   config = ActiveRecord::Base.configurations[db_name]
 
   begin
-    #activerecord 4 uses symbol
-    #TODO, remove when activerecord 3 support is dropped
-    if ActsAsTaggableOn::Utils.active_record4? || ActsAsTaggableOn::Utils.active_record5?
-      ActiveRecord::Base.establish_connection(db_name.to_sym)
-    else
-      ActiveRecord::Base.establish_connection(db_name)
-    end
+    ActiveRecord::Base.establish_connection(db_name.to_sym)
     ActiveRecord::Base.connection
   rescue
     case db_name