Laws is anxious his players cut out the mistakes which have proved costly so far this season, with skipper Darren Purse and latterly Beevers coming in for criticism.
Beevers, 19, was partly responsible for Jon Parkin's winner in the defeat to Preston in midweek.
Laws said: "I think he was fatigued a little bit towards the end on Tuesday and that's where the mistake came from.
"But he's a good player and I'm sure there will be a lot more good things to come from him."
Laws added: "We're not keeping a tight ship at the back and that's something we have to correct. It was a firm foundation for us last season."