3 files changed, 18 insertions, 2 deletions
diff --git a/activemodel/CHANGELOG.md b/activemodel/CHANGELOG.md
index f86b4804c8..fb4b972282 100644
--- a/activemodel/CHANGELOG.md
+++ b/activemodel/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   Change validates_acceptance_of to accept true by default.
+
+    The default for validates_acceptance_of is now "1" and true.
+    In the past, only "1" was the default and you were required to add 
+    accept: true.
+
 *   Remove deprecated `ActiveModel::Dirty#reset_#{attribute}` and
     `ActiveModel::Dirty#reset_changes`.
 
diff --git a/activemodel/lib/active_model/validations/acceptance.rb b/activemodel/lib/active_model/validations/acceptance.rb
index ac5e79859b..ee160fb483 100644
--- a/activemodel/lib/active_model/validations/acceptance.rb
+++ b/activemodel/lib/active_model/validations/acceptance.rb
@@ -3,12 +3,12 @@ module ActiveModel
   module Validations
     class AcceptanceValidator < EachValidator # :nodoc:
       def initialize(options)
-        super({ allow_nil: true, accept: "1" }.merge!(options))
+        super({ allow_nil: true, accept: ["1", true] }.merge!(options))
         setup!(options[:class])
       end
 
       def validate_each(record, attribute, value)
-        unless value == options[:accept]
+        unless acceptable_option?(value)
           record.errors.add(attribute, :accepted, options.except(:accept, :allow_nil))
         end
       end
@@ -20,6 +20,10 @@ module ActiveModel
         klass.send(:attr_reader, *attr_readers)
         klass.send(:attr_writer, *attr_writers)
       end
+
+      def acceptable_option?(value)
+        Array(options[:accept]).include?(value)
+      end
     end
 
     module HelperMethods
diff --git a/activemodel/test/cases/validations/acceptance_validation_test.rb b/activemodel/test/cases/validations/acceptance_validation_test.rb
index e78aa1adaf..b7872ea6bf 100644
--- a/activemodel/test/cases/validations/acceptance_validation_test.rb
+++ b/activemodel/test/cases/validations/acceptance_validation_test.rb
@@ -65,4 +65,10 @@ class AcceptanceValidationTest < ActiveModel::TestCase
   ensure
     Person.clear_validators!
   end
+
+  def test_validates_acceptance_of_true
+    Topic.validates_acceptance_of(:terms_of_service)
+
+    assert Topic.new(terms_of_service: true).valid?
+  end
 end