diff --git a/client/internal/config.go b/client/internal/config.go
index 8bee88cf0..c8edcfb88 100644
--- a/client/internal/config.go
+++ b/client/internal/config.go
@@ -27,7 +27,7 @@ const (
 )
 
 var defaultInterfaceBlacklist = []string{iface.WgInterfaceDefault, "wt", "utun", "tun0", "zt", "ZeroTier", "wg", "ts",
-	"Tailscale", "tailscale", "docker", "veth", "br-"}
+	"Tailscale", "tailscale", "docker", "veth", "br-", "lo"}
 
 // ConfigInput carries configuration changes to the client
 type ConfigInput struct {
diff --git a/client/internal/stdnet/stdnet.go b/client/internal/stdnet/stdnet.go
index c596e105e..142fea80f 100644
--- a/client/internal/stdnet/stdnet.go
+++ b/client/internal/stdnet/stdnet.go
@@ -196,6 +196,12 @@ func parseInterfacesString(interfaces string) []*transport.Interface {
 func InterfaceFilter(disallowList []string) func(string) bool {
 
 	return func(iFace string) bool {
+
+		if strings.HasPrefix(iFace, "lo") {
+			// hardcoded loopback check to support already installed agents
+			return false
+		}
+
 		for _, s := range disallowList {
 			if strings.HasPrefix(iFace, s) {
 				log.Debugf("ignoring interface %s - it is not allowed", iFace)