HCS12 Compiler warning

I get this warning:

C2705: Possible loss of data.

when compiling this code:

    char var = 8;
    var = var / 2;

If I change var from a char to a short, the warning disappears.
I tried casting the '2' above to char, but that didn't help.
Why am I gettng this warning when using a char?

Mike