depends on year, and transmission/transfer case
I know the electronic ones have switches that you can modify for tire/gear size
I know 700r4s (2wd at least) have speedometer gears which can be modified
There are also ratio boxes that you can install to correct
Or you could just learn the difference, IE: My speedo is 10% slow, if it says 32 im really doing 35(ish) and if it says 60 im really doing 66(ish). Simple, free RPM calculator will give you exact numbers for your setup
What do you have? that determines the fix