Index: lib/Mail/SpamAssassin/BayesStore/SQL.pm
===================================================================
--- lib/Mail/SpamAssassin/BayesStore/SQL.pm     (revision 553208)
+++ lib/Mail/SpamAssassin/BayesStore/SQL.pm     (working copy)
@@ -254,7 +254,7 @@
 
     unless ($rc) {
       dbg("bayes: calculate_expire_delta: SQL error: ".$self->{_dbh}->errstr());
-      return undef;
+      return ();
     }
 
     my ($count) = $sth->fetchrow_array();