diff --git a/Shorewall-perl/Shorewall/Tunnels.pm b/Shorewall-perl/Shorewall/Tunnels.pm
index bc91b5000..0e26a25a3 100644
--- a/Shorewall-perl/Shorewall/Tunnels.pm
+++ b/Shorewall-perl/Shorewall/Tunnels.pm
@@ -71,6 +71,7 @@ sub setup_tunnels() {
 
 	unless ( $gatewayzones eq '-' ) {
 	    for my $zone ( split /,/, $gatewayzones ) {
+		fatal_error "Unknown zone ($zone)" unless $zones{zone};
 		fatal_error "Invalid zone ($zone)" unless $zones{$zone}{type} eq 'ipv4';
 		$inchainref  = ensure_filter_chain "${zone}2${firewall_zone}", 1;
 		$outchainref = ensure_filter_chain "${firewall_zone}2${zone}", 1;
@@ -209,6 +210,8 @@ sub setup_tunnels() {
     sub setup_one_tunnel($$$$) {
 	my ( $kind , $zone, $gateway, $gatewayzones ) = @_;
 
+	fatal_error "Unknown zone ($zone)" unless $zones{zone};
+
 	fatal_error "Invalid zone ($zone)" unless $zones{$zone}{type} eq 'ipv4';
 
 	my $inchainref  = ensure_filter_chain "${zone}2${firewall_zone}", 1;