Carlisle boss Greg Abbott wants a mean streak after their unbeaten away record ended as Chesterfield roared to a 4-1 win.
Leon Clarke scored a hat-trick and for the third game running following his loan move from Swindon as the Spireites swept the Cumbrians aside to record their third consecutive victory.
But Abbott believes his team had a hand in their own downfall in Saturday's League One clash at the B2Net Stadium and is looking for them to toughen up and cut out the mistakes.
"We just haven't defended well enough," he said. "We gave away really soft goals and didn't defend our box well enough and that's always going to give you problems.
"We actually played quite well but we have given away four goals and it's totally unacceptable. It wasn't actually the back four's fault, it was situations where we've lost the ball and they've got into our back four too cheaply.
"They are a really good group of players but I need them to be a team of brutes and play with a nastiness and edge to them. We have given points away when our attacking play warranted a bit more."