diff --git a/library/x509_crt.c b/library/x509_crt.c
index fdcc969..315d98b 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -1492,9 +1492,9 @@
 
         md( md_info, crl_list->tbs.p, crl_list->tbs.len, hash );
 
-        if( pk_can_do( &ca->pk, crl_list->sig_pk ) == 0 ||
-            pk_verify( &ca->pk, crl_list->sig_md, hash, md_info->size,
-                       crl_list->sig.p, crl_list->sig.len ) != 0 )
+        if( pk_verify_ext( crl_list->sig_pk, crl_list->sig_opts, &ca->pk,
+                           crl_list->sig_md, hash, md_info->size,
+                           crl_list->sig.p, crl_list->sig.len ) != 0 )
         {
             flags |= BADCRL_NOT_TRUSTED;
             break;