# Define ability to change the amount in Product Policy
def amount?
  user.admin?
end

```
:::

## Raise errors when policies are missing

The default behavior of Avo is to allow missing policies for resources silently. So, if you have a `User` model and a `Avo::Resources::User` but don't have a `UserPolicy`, Avo will not raise errors regarding missing policies and authorize that resource.

If, however, you need to be on the safe side of things and raise errors when a Resource is missing a Policy, you can toggle on the `raise_error_on_missing_policy` configuration.

```ruby{7}