tcDefaults [L locn (DefaultDecl mono_tys)]
= setSrcSpan locn $
addErrCtxt defaultDeclCtxt $
- do { ovl_str <- doptM Opt_OverloadedStrings
+ do { ovl_str <- xoptM Opt_OverloadedStrings
; num_class <- tcLookupClass numClassName
; is_str_class <- tcLookupClass isStringClassName
; let deflt_clss | ovl_str = [num_class, is_str_class]