1 files changed, 5 insertions, 2 deletions
diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index d8fae495e7..76ec7eb681 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -243,11 +243,14 @@ module ActiveRecord
             # def pirate_attributes=(attributes)
             #   assign_nested_attributes_for_one_to_one_association(:pirate, attributes)
             # end
-            class_eval %{
+            class_eval <<-eoruby, __FILE__, __LINE__ + 1
+              if method_defined?(:#{association_name}_attributes=)
+                remove_method(:#{association_name}_attributes=)
+              end
               def #{association_name}_attributes=(attributes)
                 assign_nested_attributes_for_#{type}_association(:#{association_name}, attributes)
               end
-            }, __FILE__, __LINE__
+            eoruby
           else
             raise ArgumentError, "No association found for name `#{association_name}'. Has it been defined yet?"
           end