diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index 6ba3d45affeae6c410d7d6bc5c841bea71284ea0..3181ca9a327b5ad4adc1b3649892fdf0663d7bac 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -46,7 +46,7 @@ class CollectionProxy # :nodoc:
 
       delegate :select, :find, :first, :last,
                :build, :create, :create!,
-               :concat, :delete_all, :destroy_all, :delete, :destroy, :uniq,
+               :concat, :replace, :delete_all, :destroy_all, :delete, :destroy, :uniq,
                :sum, :count, :size, :length, :empty?,
                :any?, :many?, :include?,
                :to => :@association
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 1e599319636434deac5782930706a8da6b3b26ba..682e1458285a54dd8da882b0cfade506d94165de 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -1578,4 +1578,15 @@ def test_association_attributes_are_available_to_after_initialize
 
     assert_equal car.id, bulb.attributes_after_initialize['car_id']
   end
+
+  def test_replace
+    car = Car.create(:name => 'honda')
+    bulb1 = car.bulbs.create
+    bulb2 = Bulb.create
+
+    assert_equal [bulb1], car.bulbs
+    car.bulbs.replace([bulb2])
+    assert_equal [bulb2], car.bulbs
+    assert_equal [bulb2], car.reload.bulbs
+  end
 end