diff --git a/units/systemd-networkd.service.in b/units/systemd-networkd.service.in
index 01931665a4..1b69677496 100644
--- a/units/systemd-networkd.service.in
+++ b/units/systemd-networkd.service.in
@@ -33,7 +33,7 @@ ProtectKernelLogs=yes
 ProtectSystem=strict
 Restart=on-failure
 RestartSec=0
-RestrictAddressFamilies=AF_UNIX AF_NETLINK AF_INET AF_INET6 AF_PACKET
+RestrictAddressFamilies=AF_UNIX AF_NETLINK AF_INET AF_INET6 AF_PACKET AF_ALG
 RestrictNamespaces=yes
 RestrictRealtime=yes
 RestrictSUIDSGID=yes