Dapper enum to snake_case string

Hi, I have an enum

ItemType

ItemType

with values like

FileCollection

FileCollection

. In the database a string is stored in snake_case form, eg.

'file_collection'

'file_collection'

.
Dapper doesn't seem to map it automatically, even with

DefaultTypeMap.MatchNamesWithUnderscores = true;

DefaultTypeMap.MatchNamesWithUnderscores = true;

.
Anyone else had a problem like this before and can help?