diff --git a/lib/has_aux_table.rb b/lib/has_aux_table.rb
index de9640d..45e087e 100644
--- a/lib/has_aux_table.rb
+++ b/lib/has_aux_table.rb
@@ -51,6 +51,7 @@ module HasAuxTable
       setup_initialize_hook!(aux_config)
       setup_save_hook!(aux_config)
       setup_reload_hook!(aux_config)
+      setup_attributes_hook!(aux_config)
       setup_relation_extensions!(aux_config)
       setup_attribute_getter_setter_hooks!(aux_config)
 
@@ -306,6 +307,17 @@ module HasAuxTable
       end
     end
 
+    sig { params(aux_config: AuxTableConfig).void }
+    def setup_attributes_hook!(aux_config)
+      attributes_method = self.instance_method(:attributes)
+      self.define_method(:attributes) do |*args|
+        T.bind(self, ActiveRecord::Base)
+        ret = attributes_method.bind(self).call(*args)
+        ret.merge!(aux_config.aux_attributes(self))
+        ret
+      end
+    end
+
     sig do
       params(
         aux_table_name: Symbol,
diff --git a/lib/has_aux_table/aux_table_config.rb b/lib/has_aux_table/aux_table_config.rb
index c000995..28fa938 100644
--- a/lib/has_aux_table/aux_table_config.rb
+++ b/lib/has_aux_table/aux_table_config.rb
@@ -102,6 +102,14 @@ module HasAuxTable
       aux_model.assign_attributes(aux_args)
     end
 
+    sig do
+      params(main_model: ActiveRecord::Base).returns(T::Hash[Symbol, T.untyped])
+    end
+    def aux_attributes(main_model)
+      aux_model = self.ensure_aux_target(main_model)
+      aux_model.attributes.slice(*self.aux_column_names)
+    end
+
     sig { returns(T::Array[String]) }
     def aux_column_names
       @aux_column_names ||=
diff --git a/spec/active_record/aux_table_spec.rb b/spec/active_record/aux_table_spec.rb
index e10c885..3aba090 100644
--- a/spec/active_record/aux_table_spec.rb
+++ b/spec/active_record/aux_table_spec.rb
@@ -187,6 +187,20 @@ RSpec.describe HasAuxTable do
     end
   end
 
+  it "has the right #attributes" do
+    car =
+      Car.create!(name: "Honda Civic", fuel_type: "gasoline", engine_size: 2.0)
+    expect(car.attributes).to match(
+      "type" => "Car",
+      "id" => car.id,
+      "name" => "Honda Civic",
+      "fuel_type" => "gasoline",
+      "engine_size" => be_within(0.001).of(2.0),
+      "created_at" => be_within(0.001).of(car.created_at),
+      "updated_at" => be_within(0.001).of(car.updated_at)
+    )
+  end
+
   describe "database integration" do
     it "provides automatic attribute accessors for auxiliary table columns" do
       vehicle = Car.create!(name: "Honda Civic")