- Updated error check on optional nextUpdate in CRL

diff --git a/library/x509parse.c b/library/x509parse.c
index 38824b0..506be47 100644
--- a/library/x509parse.c
+++ b/library/x509parse.c
@@ -1323,7 +1323,9 @@
 
     if( ( ret = x509_get_UTCTime( &p, end, &crl->next_update ) ) != 0 )
     {
-        if ( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) {
+        if ( ret != ( POLARSSL_ERR_X509_CERT_INVALID_DATE |
+                        POLARSSL_ERR_ASN1_UNEXPECTED_TAG ) )
+        {
             x509_crl_free( crl );
             return( ret );
         }