Enum field doesn't map to the select widget by automatically in the admin page

[eirenik0]

When defining a model with some Enum column the select widget doesn't appears in the administrative panel.

[slav0nic]

from websauna.system.form.fields import JSONValue, EnumValue
from websauna.system.form.schema import enum_values
...
include = [
   ...
    colander.SchemaNode(EnumValue(Position),
                        name="position",
                        widget=deform.widget.SelectWidget(values=enum_values(Position))),]