vectorstorer: AddGeometryColumn error

[howff]

When vectorstorer tries to import a vector resource it gives the error
ProgrammingError: function addgeometrycolumn(unknown, unknown, integer, unknown, integer) does not exist
LINE 1: SELECT AddGeometryColumn ('aa5230d5-d4a1-44c2-96b5-398cd3f1f...

I see this comes from the code:
publicamundi/storers/vector/db_helpers.py calls
"SELECT AddGeometryColumn ('%s','the_geom',%s,'%s',%s);" %
(table_name, srs, geometry, coordinate_dimension))

How does it need to be modified to work correctly?

(I am using the recommended publicamundi installation on centos7 which has:
postgresql-9.3-postgis-2.1
postgresql-9.3-postgis-2.3
postgresql-9.3-postgis-2.3-scripts
postgresql-9.3-postgis-scripts
)