Symbols longer than 255 chars?

I'm using fasm to compile some machine-generated code, and some of my identifiers are longer than 255 characters. I've had a first go through the source code but it seems like this limit is embedded in the logic all over the place. The error I get, specifically, is this one, in PREPROCE.INC

Code:

 convert_symbol:
lods byte [esi]
stos byte [edi]
xlat byte [ebx]
or   al,al
loopnzd convert_symbol
neg  ecx
cmp  ecx,255
ja   name_too_long

dec  edi
mov  ebx,edi
sub  ebx,ecx
mov  byte [ebx-1],cl

I think probably I have to change that last line it to something like:

Code:

mov  byte [ebx-2],cx

But where are all the repercussions of that change? All over the place, it seems. Any suggestions on how to make this easy?