Should prisoners be made to work?

I was researching on the internet about whether prisoners get paid for labor performed while in prison. Some people say that certain jobs do but somewhere in the area of 12 cents to 17 cents or 75 dollars per month. Some say that in some states they do not get any pay.
However, what surprised me is how some responded and compared it to slavery. And how horrible it was to make them work for no pay.
Can it really be compared to slavery?