PERL_CALLCONV I32 Perl_sv_eq(pTHX_ register SV *sv1, register SV *sv2);
PERL_CALLCONV char * Perl_sv_collxfrm(pTHX_ SV *const sv, STRLEN *const nxp);
PERL_CALLCONV bool Perl_sv_2bool(pTHX_ register SV *const sv);
-PERL_CALLCONV void Perl_mro_isa_changed_in(HV* stash);
+PERL_CALLCONV void Perl_mro_isa_changed_in(pTHX_ HV* stash);
/* ref() is now a macro using Perl_doref;
* this version provided for binary compatibility only.