diff --git a/Gemfile b/Gemfile
index b25de8f..9101b91 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,3 +2,5 @@ source "http://rubygems.org"
 
 # Specify your gem's dependencies in record_with_operator.gemspec
 gemspec
+
+gem 'minitest', '~> 5.7.0'
diff --git a/README.rdoc b/README.rdoc
index 4da0dbd..84b8199 100644
--- a/README.rdoc
+++ b/README.rdoc
@@ -97,7 +97,7 @@ It's also possible to modify options for creator/updater/deleter associations.
 For example, in the case you use acts_as_paranoid and want to get creator/updater/deleter even if they are deleted,
 the configuration will be look like this.
 
-  RecordWithOperator.config[:operator_association_options] = {:with_deleted => true}
+  RecordWithOperator.config[:operator_association_scope] = -> { with_deleted }
 
 You can cange created_by, updated_by, deleted_by column name by changing RecordWithOperator.config with keys :creator_column, :updater_column and :deleter_column.
 
diff --git a/lib/record_with_operator.rb b/lib/record_with_operator.rb
index 569c409..c3ba0ff 100644
--- a/lib/record_with_operator.rb
+++ b/lib/record_with_operator.rb
@@ -5,7 +5,8 @@ def self.config
       :creator_column => "created_by",
       :updater_column => "updated_by",
       :deleter_column => "deleted_by",
-      :operator_association_options => {}}
+      :operator_association_options => {},
+      :operator_association_scope => nil}
     @config
   end
 
diff --git a/lib/record_with_operator/recorder.rb b/lib/record_with_operator/recorder.rb
index 1816403..4735566 100644
--- a/lib/record_with_operator/recorder.rb
+++ b/lib/record_with_operator/recorder.rb
@@ -7,7 +7,7 @@ def self.included(base)
     private
 
     def set_creator
-      send("#{RecordWithOperator.creator_column}=", operator.try(:id))
+      send("#{RecordWithOperator.creator_column}=", operator.try!(:id))
     end
 
     def set_updater
@@ -19,7 +19,9 @@ def set_updater
     def update_deleter
       return if frozen?
       return unless operator
-      self.class.update_all("#{RecordWithOperator.deleter_column} = #{operator.id}", ["#{self.class.primary_key} = ?", id])
+      self.class
+        .where(self.class.primary_key => id)
+        .update_all(RecordWithOperator.deleter_column => operator.id)
       send("#{RecordWithOperator.deleter_column}=", operator.id)
     end
 
@@ -36,9 +38,9 @@ def records_with_operator_on(*args)
         before_destroy :update_deleter if records_deleter?
 
         if self.table_exists?
-          belongs_to :creator, {:foreign_key => "created_by", :class_name => RecordWithOperator.config[:operator_class_name]}.merge(RecordWithOperator.config[:operator_association_options]) if records_creator?
-          belongs_to :updater, {:foreign_key => "updated_by", :class_name => RecordWithOperator.config[:operator_class_name]}.merge(RecordWithOperator.config[:operator_association_options]) if records_updater?
-          belongs_to :deleter, {:foreign_key => "deleted_by", :class_name => RecordWithOperator.config[:operator_class_name]}.merge(RecordWithOperator.config[:operator_association_options]) if records_deleter?
+          belongs_to :creator, RecordWithOperator.config[:operator_association_scope], {:foreign_key => "created_by", :class_name => RecordWithOperator.config[:operator_class_name]}.merge(RecordWithOperator.config[:operator_association_options]) if records_creator?
+          belongs_to :updater, RecordWithOperator.config[:operator_association_scope], {:foreign_key => "updated_by", :class_name => RecordWithOperator.config[:operator_class_name]}.merge(RecordWithOperator.config[:operator_association_options]) if records_updater?
+          belongs_to :deleter, RecordWithOperator.config[:operator_association_scope], {:foreign_key => "deleted_by", :class_name => RecordWithOperator.config[:operator_class_name]}.merge(RecordWithOperator.config[:operator_association_options]) if records_deleter?
         end
       end
 
diff --git a/test/record_with_operator_belongs_to_association_test.rb b/test/record_with_operator_belongs_to_association_test.rb
index 3a62ea7..6d0f44c 100644
--- a/test/record_with_operator_belongs_to_association_test.rb
+++ b/test/record_with_operator_belongs_to_association_test.rb
@@ -4,14 +4,14 @@ class User < ActiveRecord::Base
 end
 
 class NoteBelongsToMemo < ActiveRecord::Base
-  set_table_name "notes"
+  self.table_name = "notes"
   belongs_to :memo
 
   records_with_operator_on :create, :update, :destroy
 end
 
 class Memo < ActiveRecord::Base
-  set_table_name "memos"
+  self.table_name = "memos"
 
   records_with_operator_on :create, :update, :destroy
 end
diff --git a/test/record_with_operator_has_many_dependent_test.rb b/test/record_with_operator_has_many_dependent_test.rb
index 746dd98..448951d 100644
--- a/test/record_with_operator_has_many_dependent_test.rb
+++ b/test/record_with_operator_has_many_dependent_test.rb
@@ -4,7 +4,7 @@ class User < ActiveRecord::Base
 end
 
 class NoteWithUserWithDependency < ActiveRecord::Base
-  set_table_name "notes"
+  self.table_name = "notes"
   has_many :memos, :class_name => "MemoWithUserWithDependency", :foreign_key => "note_id", :dependent => :destroy
 
   before_destroy :check_operator
@@ -16,7 +16,7 @@ def check_operator
 end
 
 class MemoWithUserWithDependency < ActiveRecord::Base
-  set_table_name "memos"
+  self.table_name = "memos"
 
   before_destroy :check_operator
 
@@ -42,8 +42,8 @@ def setup
 
   def test_memos_should_be_destroyed_when_note_is_destroyed
     @note_created_by_user1.destroy
-    assert_nil NoteWithUserWithDependency.find_by_id(@note_created_by_user1.id)
-    assert MemoWithUserWithDependency.find_all_by_note_id(@note_created_by_user1.id).empty?
+    assert_nil NoteWithUserWithDependency.find_by(:id => @note_created_by_user1.id)
+    assert MemoWithUserWithDependency.where(:note_id => @note_created_by_user1.id).empty?
   end
 
 end
diff --git a/test/record_with_operator_has_one_association_test.rb b/test/record_with_operator_has_one_association_test.rb
index e5953fd..3355e26 100644
--- a/test/record_with_operator_has_one_association_test.rb
+++ b/test/record_with_operator_has_one_association_test.rb
@@ -4,14 +4,14 @@ class User < ActiveRecord::Base
 end
 
 class NoteHasOneMemo < ActiveRecord::Base
-  set_table_name "notes"
+  self.table_name = "notes"
   has_one :memo, :class_name => "Memo", :foreign_key => "note_id"
 
   records_with_operator_on :create, :update, :destroy
 end
 
 class Memo < ActiveRecord::Base
-  set_table_name "memos"
+  self.table_name = "memos"
 
   records_with_operator_on :create, :update, :destroy
 end
diff --git a/test/record_with_operator_reflection_test.rb b/test/record_with_operator_reflection_test.rb
index 43c89d2..adcc857 100644
--- a/test/record_with_operator_reflection_test.rb
+++ b/test/record_with_operator_reflection_test.rb
@@ -4,13 +4,13 @@ class User < ActiveRecord::Base
 end
 
 class NoteForReflectionTest < ActiveRecord::Base
-  set_table_name "notes"
+  self.table_name = "notes"
 
   records_with_operator_on :create, :update, :destroy
 end
 
 class CreatorNoteForReflectionTest < ActiveRecord::Base
-  set_table_name "creator_notes"
+  self.table_name = "creator_notes"
 
   records_with_operator_on :create
 end
@@ -26,18 +26,18 @@ def setup
   end
 
   def test_include
-    assert NoteForReflectionTest.find(:all, :include => [:creator, :updater])
+    assert NoteForReflectionTest.includes(:creator, :updater).all.to_a
   end
 
   def test_joins
-    assert NoteForReflectionTest.find(:all, :joins => [:creator, :updater])
+    assert NoteForReflectionTest.joins(:creator, :updater).all.to_a
   end
 
   def test_include_missing_association
-    assert_raise(ActiveRecord::ConfigurationError) { CreatorNoteForReflectionTest.find(:all, :include => [:updater]) }
+    assert_raise(ActiveRecord::ConfigurationError) { CreatorNoteForReflectionTest.includes(:updater).all.to_a }
   end
 
   def test_joins_missing_association
-    assert_raise(ActiveRecord::ConfigurationError) { CreatorNoteForReflectionTest.find(:all, :joins => [:updater]) }
+    assert_raise(ActiveRecord::ConfigurationError) { CreatorNoteForReflectionTest.joins(:updater).all.to_a }
   end
 end
diff --git a/test/record_with_operator_test.rb b/test/record_with_operator_test.rb
index a345800..b61b483 100644
--- a/test/record_with_operator_test.rb
+++ b/test/record_with_operator_test.rb
@@ -4,10 +4,10 @@ class User < ActiveRecord::Base
 end
 
 class NoteWithUser < ActiveRecord::Base
-  set_table_name "notes"
+  self.table_name = "notes"
   has_many :memos, :class_name => "MemoWithUser", :foreign_key => "note_id"
 
-  scope :new_arrivals, {:order => "updated_at desc"}
+  scope :new_arrivals, -> { order("updated_at" => "desc") }
 
   alias_method :destroy!, :destroy
 
@@ -16,7 +16,7 @@ class NoteWithUser < ActiveRecord::Base
   def destroy
     with_transaction_returning_status do
       _run_destroy_callbacks do
-        self.class.update_all({:deleted_at => Time.now}, {self.class.primary_key => self.id})
+        self.class.where(self.class.primary_key => self.id).update_all(:deleted_at => Time.now)
       end
     end
     freeze
@@ -28,25 +28,25 @@ def deleted?
 end
 
 class SimpleNoteWithUser < ActiveRecord::Base
-  set_table_name "simple_notes"
+  self.table_name = "simple_notes"
 end
 
 class MemoWithUser < ActiveRecord::Base
-  set_table_name "memos"
+  self.table_name = "memos"
 
-  scope :new_arrivals, {:order => "updated_at desc"}
+  scope :new_arrivals, -> { order("updated_at" => "desc") }
 
   records_with_operator_on :create, :update, :destroy
 end
 
 class UpdaterNoteWithUser < ActiveRecord::Base
-  set_table_name "updater_notes"
+  self.table_name = "updater_notes"
 
   records_with_operator_on :update
 end
 
 class DeleterNoteWithUser < ActiveRecord::Base
-  set_table_name "deleter_notes"
+  self.table_name = "deleter_notes"
 
   records_with_operator_on :destroy
 
@@ -199,21 +199,21 @@ def test_manualy_found_memo_should_have_operator
     RecordWithOperator.operator = @user2
     note = NoteWithUser.find(@note_created_by_user1.id)
     note.memos.create!(:body => "memo")
-    assert_equal @user2, note.memos.find(:first).operator
+    assert_equal @user2, note.memos.first.operator
   end
 
   def test_dynamically_found_memo_should_have_operator
     RecordWithOperator.operator = @user2
     note = NoteWithUser.find(@note_created_by_user1.id)
     note.memos.create!(:body => "memo")
-    assert_equal @user2, note.memos.find_by_body("memo").operator
+    assert_equal @user2, note.memos.find_by(:body => "memo").operator
   end
 
   def test_dynamically_found_memos_should_have_operator
     RecordWithOperator.operator = @user2
     note = NoteWithUser.find(@note_created_by_user1.id)
     note.memos.create!(:body => "memo")
-    assert note.memos.find_all_by_body("memo").all?{|m| m.operator == @user2}
+    assert note.memos.where(:body => "memo").all?{|m| m.operator == @user2}
   end
 
   def test_found_memo_through_named_scope_should_have_operator
@@ -227,7 +227,7 @@ def test_dynamically_found_memo_through_named_scope_should_have_operator
     RecordWithOperator.operator = @user2
     note = NoteWithUser.find(@note_created_by_user1.id)
     note.memos.create!(:body => "memo")
-    assert_equal @user2, note.memos.new_arrivals.find_by_body("memo").operator
+    assert_equal @user2, note.memos.new_arrivals.find_by(:body => "memo").operator
   end
 
   def test_auto_found_memo_first_should_be_nil_if_note_has_no_memo
@@ -247,19 +247,19 @@ def test_auto_found_memo_last_should_be_nil_if_note_has_no_memo
   def test_manualy_found_memo_first_should_be_nil_if_note_has_no_memo
     RecordWithOperator.operator = @user2
     note = NoteWithUser.find(@note_created_by_user1.id)
-    assert_equal nil, note.memos.find(:first)
+    assert_equal nil, note.memos.first
   end
 
   def test_manualy_found_memo_last_should_be_nil_if_note_has_no_memo
     RecordWithOperator.operator = @user2
     note = NoteWithUser.find(@note_created_by_user1.id)
-    assert_equal nil, note.memos.find(:last)
+    assert_equal nil, note.memos.last
   end
 
   def test_dynamically_found_memos_first_should_be_nil_if_note_has_no_memo
     RecordWithOperator.operator = @user2
     note = NoteWithUser.find(@note_created_by_user1.id)
-    assert_equal nil, note.memos.find_all_by_body("memo").first
+    assert_equal nil, note.memos.where(:body => "memo").first
   end
 
   def test_found_memo_through_named_scope_last_should_be_nil_if_note_has_no_memo
diff --git a/test/record_with_operator_user_class_name_test.rb b/test/record_with_operator_user_class_name_test.rb
index e5570ea..ba85e65 100644
--- a/test/record_with_operator_user_class_name_test.rb
+++ b/test/record_with_operator_user_class_name_test.rb
@@ -4,7 +4,7 @@
 RecordWithOperator.config[:operator_class_name] = "AdminUser"
 
 class NoteWithAdminUser < ActiveRecord::Base
-  set_table_name "notes"
+  self.table_name = "notes"
 
   records_with_operator_on :create, :update, :destroy
 
@@ -22,7 +22,7 @@ def deleted?
 end
 
 class AdminUser < ActiveRecord::Base
-  set_table_name "users"
+  self.table_name = "users"
 end
 
 class RecordWithOperatorUserClassNameTest < ActiveSupport::TestCase
diff --git a/test/test_helper.rb b/test/test_helper.rb
index fd0e4f2..f021221 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,7 +1,7 @@
 $:.push File.expand_path('../../', __FILE__)
 
 require 'logger'
-require 'test/unit'
+require 'minitest/autorun'
 require 'active_record'
 require 'active_support'
 require 'active_support/test_case'
@@ -11,5 +11,6 @@
 config = YAML::load(IO.read(File.dirname(__FILE__) + '/database.yml'))
 ActiveRecord::Base.logger = Logger.new(File.dirname(__FILE__) + "/debug.log")
 ActiveRecord::Base.establish_connection(config['sqlite3'])
+ActiveSupport::TestCase.test_order = :random
 
 load(File.dirname(__FILE__) + "/schema.rb")