A liner assembly tool includes a base pipe (306) that includes a bore (308) therethrough; a wellbore liner (312) that includes a liner top and is coupled to the base pipe; a pack-off element (328) radially positioned between the base pipe and the wellbore liner to ride on the base pipe; and a wedge (334) positioned to ride on the base pipe and expand the pack-off element to at least partially sealthe liner top to a wellbore wall based on a particular fluid pressure supplied through the bore.