PostGIS 2.x requires ST_GeometryFromText?

I'm not sure if this is the correct fix to this but it worked for me. points_as_polygon tries to call GeometryFromText instead of ST_GeometryFromText.

Running:

    select points_as_polygon('select id,x,y from ...');

I received:

    ERROR:  function geometryfromtext(unknown, integer) does not exist
    LINE 1: select 1 as gid, GeometryFromText('POLYGON((1589842.23558516...

Rebuilding the function with this change resolved the error.