diff --git a/zmldapsync/zmldapsync.pl b/zmldapsync/zmldapsync.pl
index 7f236f2..618931e 100755
--- a/zmldapsync/zmldapsync.pl
+++ b/zmldapsync/zmldapsync.pl
@@ -357,6 +357,7 @@ DOMAIN: foreach my $domain ( keys $conf->{domains} ) {
              not defined $ext_users->{$user}->{$attr} ) {
           # If the attribute doesn't exist in external LDAP, we must remove it from Zimbra.
           # Except for sn which is mandatory in Zimbra
+          log_verbose( "Attribute $attr for user $user removed from LDAP, removing it from Zimbra");
           $attrs .= '-' . $conf->{domains}->{$domain}->{users}->{attr_map}->{$attr} . " " .
 	            zim_attr_value( $zim_users->{$user}->{$conf->{domains}->{$domain}->{users}->{attr_map}->{$attr}} );
         } elsif (
@@ -370,7 +371,7 @@ DOMAIN: foreach my $domain ( keys $conf->{domains} ) {
             $attrs .= " " . $conf->{domains}->{$domain}->{users}->{attr_map}->{$attr} . " " .
 	              zim_attr_value( $ext_users->{$user}->{$attr} );
             log_verbose( "Attribute $attr for user $user changed from " .
-                       $zim_users->{$user}->{$conf->{domains}->{$domain}->{users}->{attr_map}->{$attr}} .
+                       ( $zim_users->{$user}->{$conf->{domains}->{$domain}->{users}->{attr_map}->{$attr}} || 'an empty value' ).
                        " to " .
                        $ext_users->{$user}->{$attr} );
         }