Unittest error no such function: to_tsvector

[chrisspen]

I have a package that runs some unittests on a Django model with a VectorField. Since Django runs its unittests with an in-memory Sqlite3 database that doesn't support VectorField, it throws the error:

  File "/usr/local/myproject/.env/local/lib/python2.7/site-packages/django/db/models/base.py", line 546, in save
    force_update=force_update, update_fields=update_fields)
  File "/usr/local/myproject/.env/local/lib/python2.7/site-packages/django/db/models/base.py", line 664, in save_base
    update_fields=update_fields, raw=raw, using=using)
  File "/usr/local/myproject/.env/local/lib/python2.7/site-packages/django/dispatch/dispatcher.py", line 170, in send
    response = receiver(signal=self, sender=sender, **named)
  File "/usr/local/myproject/.env/local/lib/python2.7/site-packages/djorm_pgfulltext/models.py", line 47, in auto_update_search_field_handler
    instance.update_search_field()
  File "/usr/local/myproject/.env/local/lib/python2.7/site-packages/djorm_pgfulltext/models.py", line 111, in update_search_field
    self._fts_manager.update_search_field(pk=self.pk, using=using, config=config)
  File "/usr/local/myproject/.env/local/lib/python2.7/site-packages/djorm_pgfulltext/models.py", line 169, in update_search_field
    cursor.execute(sql, params)
  File "/usr/local/myproject/.env/local/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py", line 366, in execute
    six.reraise(utils.DatabaseError, utils.DatabaseError(*tuple(e.args)), sys.exc_info()[2])
  File "/usr/local/myproject/.env/local/lib/python2.7/site-packages/django/db/backends/sqlite3/base.py", line 362, in execute
    return Database.Cursor.execute(self, query, params)
DatabaseError: no such function: to_tsvector

How would I work around this, just so my unittests will run? I'm not testing the full text search. I just need it to not break everything in Sqlite. Is there someway to make the field revert to a simple CharField just for Sqlite?