diff --git a/pve-bridge b/pve-bridge
index f63be85e..8e50112c 100755
--- a/pve-bridge
+++ b/pve-bridge
@@ -29,6 +29,7 @@ my $bridge = $net->{bridge};
 die "unable to get bridge setting\n" if !$bridge;
 
 my $bridgemtu = PVE::Tools::file_read_firstline("/sys/class/net/$bridge/mtu");
+die "bridge '$bridge' does not exist\n" if !$bridgemtu;
 
 system ("/sbin/ifconfig $iface 0.0.0.0 promisc up mtu $bridgemtu") == 0 ||
     die "interface activation failed\n";