1 files changed, 2 insertions, 3 deletions
diff --git a/activerecord/lib/active_record/attribute_methods/primary_key.rb b/activerecord/lib/active_record/attribute_methods/primary_key.rb
index 8e0b3e1402..51389c84d6 100644
--- a/activerecord/lib/active_record/attribute_methods/primary_key.rb
+++ b/activerecord/lib/active_record/attribute_methods/primary_key.rb
@@ -111,9 +111,8 @@ module ActiveRecord
         #   end
         #   Project.primary_key # => "foo_id"
         def primary_key=(value)
-          @original_primary_key = @primary_key if defined?(@primary_key)
-          @primary_key          = value && value.to_s
-          @quoted_primary_key   = nil
+          @primary_key        = value && value.to_s
+          @quoted_primary_key = nil
         end
       end
     end