diff --git a/Shorewall/Perl/Shorewall/Zones.pm b/Shorewall/Perl/Shorewall/Zones.pm
index 378c7471e..62d6f4b1e 100644
--- a/Shorewall/Perl/Shorewall/Zones.pm
+++ b/Shorewall/Perl/Shorewall/Zones.pm
@@ -903,6 +903,8 @@ sub process_interface( $$ ) {
 	$root = $interface;
     }
 
+    fatal_error "Invalid interface name ($interface)" if $interface =~ /\*/;
+
     my $physical = $interface;
     my $broadcasts;
 
@@ -1183,6 +1185,8 @@ sub known_interface($;$)
 
     return $interfaceref if $interfaceref;
 
+    fatal_error "Invalid interface ($interface)" if $interface =~ /\*/;
+
     for my $i ( @interfaces ) {
 	$interfaceref = $interfaces{$i};
 	my $root = $interfaceref->{root};