ddef_t *ED_FieldAtOfs(int ofs);
qboolean ED_ParseEpair(edict_t *ent, ddef_t *key, const char *s);
-cvar_t pr_checkextension = {0, "pr_checkextension", "1"};
+cvar_t pr_checkextension = {CVAR_READONLY, "pr_checkextension", "1"};
cvar_t nomonsters = {0, "nomonsters", "0"};
cvar_t gamecfg = {0, "gamecfg", "0"};
cvar_t scratch1 = {0, "scratch1", "0"};