Need to include protease inhibitor in IP wash buffer? - (Sep/19/2015 )

Is it necessary to include a protease inhibitor in the IP wash buffer? My lysates have protease inhibitors during incubation with antibody and beads but the wash is short and done at 4C and tubes kept on ice. Therefore I was not sure if the wash buffer needed the protease inhibitor. Seems kind of wasteful. 

Thanks!

I always use protease inhibitors - lysis and washes. What would be wasteful is to have a sub-optimal experiment because of a change in protocol. At least that's how I see it.