diff --git a/pkg/tcpip/link/sniffer/sniffer.go b/pkg/tcpip/link/sniffer/sniffer.go
index 12f1fa5b6..fb85ae4c9 100644
--- a/pkg/tcpip/link/sniffer/sniffer.go
+++ b/pkg/tcpip/link/sniffer/sniffer.go
@@ -244,7 +244,7 @@ func logPacket(prefix string, dir direction, protocol tcpip.NetworkProtocolNumbe
 		)
 		return
 	default:
-		log.Infof("%s%s unknown network protocol", prefix, directionPrefix)
+		log.Infof("%s%s unknown network protocol: %d", prefix, directionPrefix, protocol)
 		return
 	}