Trigraph in next

I get this warning compiling next now:

p_saveg.c: In function 'P_UnArchiveLuabanksAndConsistency': p_saveg.c:4536:65: error: trigraph ??) ignored, use -trigraphs to enable [-Werror=trigraphs] CONS_Alert(CONS_ERROR, M_GetText("Failed consistency check (???)\n"));

I'm using GCC81. Should -Wno-trigraphs be added to the make options, or should the string just be changed?