4 files changed, 21 insertions, 27 deletions
diff --git a/activerecord/lib/active_record/attribute/user_provided_default.rb b/activerecord/lib/active_record/attribute/user_provided_default.rb
index 29d37ac689..e0bee8c17e 100644
--- a/activerecord/lib/active_record/attribute/user_provided_default.rb
+++ b/activerecord/lib/active_record/attribute/user_provided_default.rb
@@ -3,8 +3,9 @@ require 'active_record/attribute'
 module ActiveRecord
   class Attribute # :nodoc:
     class UserProvidedDefault < FromUser
-      def initialize(name, value, type)
+      def initialize(name, value, type, database_default)
         super(name, value, type)
+        @database_default = database_default
       end
 
       def type_cast(value)
@@ -14,6 +15,18 @@ module ActiveRecord
           super
         end
       end
+
+      def changed_in_place_from?(old_value)
+        super || changed_from?(database_default.value)
+      end
+
+      def with_type(type)
+        self.class.new(name, value_before_type_cast, type, database_default)
+      end
+
+      protected
+
+      attr_reader :database_default
     end
   end
 end
diff --git a/activerecord/lib/active_record/attributes.rb b/activerecord/lib/active_record/attributes.rb
index e574aebd6c..c89099589e 100644
--- a/activerecord/lib/active_record/attributes.rb
+++ b/activerecord/lib/active_record/attributes.rb
@@ -242,6 +242,7 @@ module ActiveRecord
             name,
             value,
             type,
+            _default_attributes[name],
           )
         else
           default_attribute = Attribute.from_database(name, value, type)
diff --git a/activerecord/test/cases/attributes_test.rb b/activerecord/test/cases/attributes_test.rb
index 4619293ac6..eeda9335ad 100644
--- a/activerecord/test/cases/attributes_test.rb
+++ b/activerecord/test/cases/attributes_test.rb
@@ -135,6 +135,12 @@ module ActiveRecord
       assert_equal 2, klass.new.counter
     end
 
+    test "user provided defaults are persisted even if unchanged" do
+      model = OverloadedType.create!
+
+      assert_equal "the overloaded default", model.reload.string_with_default
+    end
+
     if current_adapter?(:PostgreSQLAdapter)
       test "arrays types can be specified" do
         klass = Class.new(OverloadedType) do
diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index 3a7cc572e6..216f228142 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -623,32 +623,6 @@ class DirtyTest < ActiveRecord::TestCase
     end
   end
 
-  test "defaults with type that implements `serialize`" do
-    type = Class.new(ActiveRecord::Type::Value) do
-      def cast(value)
-        value.to_i
-      end
-
-      def serialize(value)
-        value.to_s
-      end
-    end
-
-    model_class = Class.new(ActiveRecord::Base) do
-      self.table_name = 'numeric_data'
-      attribute :foo, type.new, default: 1
-    end
-
-    model = model_class.new
-    assert_not model.foo_changed?
-
-    model = model_class.new(foo: 1)
-    assert_not model.foo_changed?
-
-    model = model_class.new(foo: '1')
-    assert_not model.foo_changed?
-  end
-
   test "in place mutation detection" do
     pirate = Pirate.create!(catchphrase: "arrrr")
     pirate.catchphrase << " matey!"