XML datatype instance has too many levels of nested nodes. Maximum allowed depth is 128 levels

This is the error message I get when running the query below: > Msg 6335, Level 16, State 102, Line 43 XML datatype instance has too > many levels of nested nodes. Maximum allowed depth is 128 levels.

SELECT *, cast(plantext as xml)
  FROM [my_database].[dbo].[the_PlanHistory]
  where servername='myServer'
  and procname='MyProcedure'
  order by cachedtime desc

I know the problem is related to the cast to xml, how can I fix it, or work around it?