dropPrimaryKey without constraint name on sql server doesn't honour schema information

I'm trying to drop a primary key from a table. The XML that I'm using in liquibase to accomplish that is:

The generated Query for SQL-Server looks like

and what's missing is the schema condition. If it should support any Schemaname the Query should look like:

select @pkname=o.name
from sysindexes i
join sysobjects o ON i.id = o.id
join sysobjects pk ON i.name = pk.name
AND pk.parent_obj = i.id
AND pk.xtype = 'PK'
join sysindexkeys ik on i.id = ik.id
AND i.indid = ik.indid
join syscolumns c ON ik.id = c.id
AND ik.colid = c.colid

INNER JOIN sysusers su ON o.uid = su.uid

where o.name = 'MY_TABLE'

and su.name = 'MY_SCHEMA'

This Bug affects the following class only

liquibase.sqlgenerator.core.DropPrimaryKeyGenerator

Let me know if you need any more information.