Schema change in master-slave setup

Hello

I have an openldap master-slave setup, and I need to make a simple schema change to add an attribute to an objectclass which is defined as below:

objectclass ( dgMail:1.2.2 NAME 'dgMailAuth' DESC 'SASL Authentication for mail' SUP top STRUCTURAL MUST dgDBID MAY ( uid $ userPassword $ mail ) )

I just need to add an attribute called mailDrop, which is already defined in the schema, but only used in other objectclasses, so the last line would become

MAY ( uid $ userPassword $ mail $ mailDrop ) )

My question is: is it safe to do this one server at a time, editing the schema file and restarting the daemon, or will I have problems with the temporary schema mismatch? I would like to minimize the downtime of the operation, since the system is heavily used in production.

Thanks in advance, Andre