diff --git a/src/basic/socket-util.c b/src/basic/socket-util.c
index 537f1e8c64..e66bc426a4 100644
--- a/src/basic/socket-util.c
+++ b/src/basic/socket-util.c
@@ -1,9 +1,10 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <arpa/inet.h>
 #include <errno.h>
 #include <limits.h>
-#include <net/if.h>
 #include <netdb.h>
 #include <netinet/ip.h>
 #include <poll.h>
diff --git a/src/core/bpf-firewall.c b/src/core/bpf-firewall.c
index 3bac231c97..185ed7d070 100644
--- a/src/core/bpf-firewall.c
+++ b/src/core/bpf-firewall.c
@@ -1,12 +1,13 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <arpa/inet.h>
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/bpf_insn.h>
 #include <net/ethernet.h>
-#include <net/if.h>
 #include <netinet/ip.h>
 #include <netinet/ip6.h>
 #include <stddef.h>
diff --git a/src/libsystemd-network/dhcp-network.c b/src/libsystemd-network/dhcp-network.c
index 1f4ad095d5..2e73983d6b 100644
--- a/src/libsystemd-network/dhcp-network.c
+++ b/src/libsystemd-network/dhcp-network.c
@@ -3,15 +3,16 @@
   Copyright © 2013 Intel Corporation. All rights reserved.
 ***/
 
-#include <errno.h>
-#include <net/ethernet.h>
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
-#include <net/if_arp.h>
-#include <stdio.h>
-#include <string.h>
+#include <errno.h>
 #include <linux/filter.h>
 #include <linux/if_infiniband.h>
 #include <linux/if_packet.h>
+#include <net/ethernet.h>
+#include <net/if_arp.h>
+#include <stdio.h>
+#include <string.h>
 
 #include "dhcp-network.h"
 #include "dhcp-protocol.h"
diff --git a/src/libsystemd-network/icmp6-util.c b/src/libsystemd-network/icmp6-util.c
index 070e94add1..d4b7ae5855 100644
--- a/src/libsystemd-network/icmp6-util.c
+++ b/src/libsystemd-network/icmp6-util.c
@@ -3,7 +3,10 @@
   Copyright © 2014 Intel Corporation. All rights reserved.
 ***/
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <errno.h>
+#include <linux/if_packet.h>
 #include <netinet/icmp6.h>
 #include <netinet/in.h>
 #include <netinet/ip6.h>
@@ -11,8 +14,6 @@
 #include <string.h>
 #include <sys/types.h>
 #include <unistd.h>
-#include <net/if.h>
-#include <linux/if_packet.h>
 
 #include "fd-util.h"
 #include "icmp6-util.h"
diff --git a/src/libsystemd-network/test-acd.c b/src/libsystemd-network/test-acd.c
index 4b5ad70cf1..6ed7260a72 100644
--- a/src/libsystemd-network/test-acd.c
+++ b/src/libsystemd-network/test-acd.c
@@ -1,11 +1,12 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <errno.h>
+#include <linux/veth.h>
 #include <stdlib.h>
 #include <unistd.h>
 
-#include <linux/veth.h>
-#include <net/if.h>
 
 #include "sd-event.h"
 #include "sd-ipv4acd.h"
diff --git a/src/libsystemd-network/test-ipv4ll-manual.c b/src/libsystemd-network/test-ipv4ll-manual.c
index 5dc6b10347..b4e6d2428f 100644
--- a/src/libsystemd-network/test-ipv4ll-manual.c
+++ b/src/libsystemd-network/test-ipv4ll-manual.c
@@ -1,10 +1,11 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include <errno.h>
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
+#include <errno.h>
+#include <linux/veth.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <linux/veth.h>
 
 #include "sd-event.h"
 #include "sd-ipv4ll.h"
diff --git a/src/libsystemd/sd-netlink/test-netlink.c b/src/libsystemd/sd-netlink/test-netlink.c
index fb3150f131..cf19c48213 100644
--- a/src/libsystemd/sd-netlink/test-netlink.c
+++ b/src/libsystemd/sd-netlink/test-netlink.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <netinet/ether.h>
 #include <netinet/in.h>
diff --git a/src/libudev/libudev-device.c b/src/libudev/libudev-device.c
index 7b9f54c976..50e2459a06 100644
--- a/src/libudev/libudev-device.c
+++ b/src/libudev/libudev-device.c
@@ -1,11 +1,12 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <ctype.h>
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <linux/sockios.h>
-#include <net/if.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
diff --git a/src/network/netdev/bridge.c b/src/network/netdev/bridge.c
index 3e394edadf..d426c0c501 100644
--- a/src/network/netdev/bridge.c
+++ b/src/network/netdev/bridge.c
@@ -1,9 +1,10 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
-#include <netinet/in.h>
 #include <linux/if_arp.h>
 #include <linux/if_bridge.h>
+#include <netinet/in.h>
 
 #include "bridge.h"
 #include "netlink-util.h"
diff --git a/src/network/netdev/fou-tunnel.c b/src/network/netdev/fou-tunnel.c
index 3bf41a8bf2..bddee5e98c 100644
--- a/src/network/netdev/fou-tunnel.c
+++ b/src/network/netdev/fou-tunnel.c
@@ -1,7 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include <linux/fou.h>
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
+#include <linux/fou.h>
 #include <netinet/in.h>
 #include <linux/ip.h>
 
diff --git a/src/network/netdev/geneve.c b/src/network/netdev/geneve.c
index bc655ec7ff..22c2b00e1b 100644
--- a/src/network/netdev/geneve.c
+++ b/src/network/netdev/geneve.c
@@ -1,8 +1,9 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
-#include <netinet/in.h>
 #include <linux/if_arp.h>
+#include <netinet/in.h>
 
 #include "alloc-util.h"
 #include "conf-parser.h"
diff --git a/src/network/netdev/ipvlan.c b/src/network/netdev/ipvlan.c
index 05d5d010f6..51ae64341d 100644
--- a/src/network/netdev/ipvlan.c
+++ b/src/network/netdev/ipvlan.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <netinet/in.h>
 #include <linux/if_arp.h>
diff --git a/src/network/netdev/macvlan.c b/src/network/netdev/macvlan.c
index 85011e11de..21933d3970 100644
--- a/src/network/netdev/macvlan.c
+++ b/src/network/netdev/macvlan.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <netinet/in.h>
 #include <linux/if_arp.h>
diff --git a/src/network/netdev/netdev.c b/src/network/netdev/netdev.c
index 894cec44cb..229520dfb2 100644
--- a/src/network/netdev/netdev.c
+++ b/src/network/netdev/netdev.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <netinet/in.h>
 #include <linux/if_arp.h>
diff --git a/src/network/netdev/tuntap.c b/src/network/netdev/tuntap.c
index 97b4b928e7..f5be31ed94 100644
--- a/src/network/netdev/tuntap.c
+++ b/src/network/netdev/tuntap.c
@@ -1,13 +1,14 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <errno.h>
 #include <fcntl.h>
-#include <net/if.h>
+#include <linux/if_tun.h>
 #include <netinet/if_ether.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
-#include <linux/if_tun.h>
 
 #include "alloc-util.h"
 #include "daemon-util.h"
diff --git a/src/network/netdev/veth.c b/src/network/netdev/veth.c
index e0f5b4ebb1..78555286d1 100644
--- a/src/network/netdev/veth.c
+++ b/src/network/netdev/veth.c
@@ -1,10 +1,11 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include <errno.h>
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
-#include <netinet/in.h>
+#include <errno.h>
 #include <linux/if_arp.h>
 #include <linux/veth.h>
+#include <netinet/in.h>
 
 #include "netlink-util.h"
 #include "veth.h"
diff --git a/src/network/netdev/vlan.c b/src/network/netdev/vlan.c
index adbba14a6e..60e49a5b8a 100644
--- a/src/network/netdev/vlan.c
+++ b/src/network/netdev/vlan.c
@@ -1,7 +1,8 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include <errno.h>
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
+#include <errno.h>
 #include <linux/if_arp.h>
 #include <linux/if_vlan.h>
 
diff --git a/src/network/netdev/vrf.c b/src/network/netdev/vrf.c
index b75ec2bcc6..24079a7203 100644
--- a/src/network/netdev/vrf.c
+++ b/src/network/netdev/vrf.c
@@ -1,8 +1,9 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
-#include <netinet/in.h>
 #include <linux/if_arp.h>
+#include <netinet/in.h>
 
 #include "vrf.h"
 
diff --git a/src/network/netdev/vxlan.c b/src/network/netdev/vxlan.c
index f333abc6c0..37f65967a6 100644
--- a/src/network/netdev/vxlan.c
+++ b/src/network/netdev/vxlan.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <netinet/in.h>
 #include <linux/if_arp.h>
diff --git a/src/network/netdev/wireguard.c b/src/network/netdev/wireguard.c
index 95c9c8c330..fed1be8d11 100644
--- a/src/network/netdev/wireguard.c
+++ b/src/network/netdev/wireguard.c
@@ -3,11 +3,12 @@
   Copyright © 2015-2017 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
 ***/
 
-#include <sys/ioctl.h>
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
-#include <netinet/in.h>
 #include <linux/if_arp.h>
 #include <linux/ipv6_route.h>
+#include <netinet/in.h>
+#include <sys/ioctl.h>
 
 #include "sd-resolve.h"
 
diff --git a/src/network/networkctl.c b/src/network/networkctl.c
index fab9ff465b..56fa373b1d 100644
--- a/src/network/networkctl.c
+++ b/src/network/networkctl.c
@@ -1,9 +1,10 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <arpa/inet.h>
 #include <getopt.h>
 #include <linux/if_addrlabel.h>
-#include <net/if.h>
 #include <stdbool.h>
 #include <sys/stat.h>
 #include <sys/types.h>
diff --git a/src/network/networkd-address-label.c b/src/network/networkd-address-label.c
index 745b959f77..e91ce3d2fa 100644
--- a/src/network/networkd-address-label.c
+++ b/src/network/networkd-address-label.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <linux/if_addrlabel.h>
 
diff --git a/src/network/networkd-bridge-mdb.c b/src/network/networkd-bridge-mdb.c
index bd1a9745dc..7ff4a18846 100644
--- a/src/network/networkd-bridge-mdb.c
+++ b/src/network/networkd-bridge-mdb.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <linux/if_bridge.h>
 
diff --git a/src/network/networkd-can.c b/src/network/networkd-can.c
index b8a1871a35..a5b003ad22 100644
--- a/src/network/networkd-can.c
+++ b/src/network/networkd-can.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <linux/can/netlink.h>
 
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 192e9df979..bac44a3858 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <netinet/in.h>
 #include <linux/if.h>
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 880856f596..d42ded6160 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <netinet/in.h>
 #include <linux/netdevice.h>
diff --git a/src/network/networkd-nexthop.c b/src/network/networkd-nexthop.c
index b07feede2b..1b44ef320c 100644
--- a/src/network/networkd-nexthop.c
+++ b/src/network/networkd-nexthop.c
@@ -2,6 +2,7 @@
  * Copyright © 2019 VMware, Inc.
  */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <linux/nexthop.h>
 
diff --git a/src/network/networkd-routing-policy-rule.c b/src/network/networkd-routing-policy-rule.c
index bb757eed71..886b4da8e0 100644
--- a/src/network/networkd-routing-policy-rule.c
+++ b/src/network/networkd-routing-policy-rule.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <linux/fib_rules.h>
 
diff --git a/src/network/test-network-tables.c b/src/network/test-network-tables.c
index 564ca09609..96f5b4d705 100644
--- a/src/network/test-network-tables.c
+++ b/src/network/test-network-tables.c
@@ -1,5 +1,9 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
+#include <linux/if.h>
+
 #include "bond.h"
 #include "dhcp6-internal.h"
 #include "dhcp6-protocol.h"
diff --git a/src/nspawn/nspawn-network.c b/src/nspawn/nspawn-network.c
index e89f087aea..1e804a2be3 100644
--- a/src/nspawn/nspawn-network.c
+++ b/src/nspawn/nspawn-network.c
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
 #include <net/if.h>
 #include <linux/if.h>
 #include <linux/nl80211.h>
diff --git a/src/shared/firewall-util-iptables.c b/src/shared/firewall-util-iptables.c
index b70b74074b..044d2d0744 100644
--- a/src/shared/firewall-util-iptables.c
+++ b/src/shared/firewall-util-iptables.c
@@ -1,19 +1,12 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-/* Temporary work-around for broken glibc vs. linux kernel header definitions
- * This is already fixed upstream, remove this when distributions have updated.
- */
-#define _NET_IF_H 1
-
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <arpa/inet.h>
 #include <endian.h>
 #include <errno.h>
 #include <stddef.h>
 #include <string.h>
-#include <net/if.h>
-#ifndef IFNAMSIZ
-#define IFNAMSIZ 16
-#endif
 #include <linux/if.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
 #include <linux/netfilter/nf_nat.h>
diff --git a/src/shared/socket-netlink.c b/src/shared/socket-netlink.c
index 6865b045b5..a126d5d73b 100644
--- a/src/shared/socket-netlink.c
+++ b/src/shared/socket-netlink.c
@@ -1,9 +1,10 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <arpa/inet.h>
 #include <errno.h>
 #include <linux/net_namespace.h>
-#include <net/if.h>
 #include <string.h>
 
 #include "alloc-util.h"
diff --git a/src/test/test-arphrd-util.c b/src/test/test-arphrd-util.c
index d81feff015..15b7997750 100644
--- a/src/test/test-arphrd-util.c
+++ b/src/test/test-arphrd-util.c
@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <linux/if_arp.h>
 
 #include "arphrd-util.h"
diff --git a/src/test/test-local-addresses.c b/src/test/test-local-addresses.c
index e3d6c08d14..f418f3712d 100644
--- a/src/test/test-local-addresses.c
+++ b/src/test/test-local-addresses.c
@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <linux/if.h>
 #include <stdio.h>
 
diff --git a/src/test/test-netlink-manual.c b/src/test/test-netlink-manual.c
index 73943bf428..f03fcffc62 100644
--- a/src/test/test-netlink-manual.c
+++ b/src/test/test-netlink-manual.c
@@ -1,5 +1,7 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <arpa/inet.h>
 #include <linux/if_tunnel.h>
 #include <linux/ip.h>
diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c
index 0d87a35288..ac4541edd7 100644
--- a/src/udev/udev-builtin-net_id.c
+++ b/src/udev/udev-builtin-net_id.c
@@ -12,9 +12,10 @@
  * When the code here is changed, man/systemd.net-naming-scheme.xml must be updated too.
  */
 
+/* Make sure the net/if.h header is included before any linux/ one */
+#include <net/if.h>
 #include <errno.h>
 #include <fcntl.h>
-#include <net/if.h>
 #include <stdarg.h>
 #include <unistd.h>
 #include <linux/if.h>