diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index a3d4707505a..3ce5fa63e0e 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -202,6 +202,7 @@ static __net_init int loopback_net_init(struct net *net)
 	if (err)
 		goto out_free_netdev;
 
+	BUG_ON(dev->ifindex != LOOPBACK_IFINDEX);
 	net->loopback_dev = dev;
 	return 0;
 
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 80a3de4906d..91914fa8ac9 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -928,7 +928,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *o
 		.saddr = oldflp->saddr,
 		.flowidn_scope = RT_SCOPE_UNIVERSE,
 		.flowidn_mark = oldflp->flowidn_mark,
-		.flowidn_iif = init_net.loopback_dev->ifindex,
+		.flowidn_iif = LOOPBACK_IFINDEX,
 		.flowidn_oif = oldflp->flowidn_oif,
 	};
 	struct dn_route *rt = NULL;
@@ -946,7 +946,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowidn *o
 		       "dn_route_output_slow: dst=%04x src=%04x mark=%d"
 		       " iif=%d oif=%d\n", le16_to_cpu(oldflp->daddr),
 		       le16_to_cpu(oldflp->saddr),
-		       oldflp->flowidn_mark, init_net.loopback_dev->ifindex,
+		       oldflp->flowidn_mark, LOOPBACK_IFINDEX,
 		       oldflp->flowidn_oif);
 
 	/* If we have an output interface, verify its a DECnet device */
@@ -1009,7 +1009,7 @@ source_ok:
 			if (!fld.daddr)
 				goto out;
 		}
-		fld.flowidn_oif = init_net.loopback_dev->ifindex;
+		fld.flowidn_oif = LOOPBACK_IFINDEX;
 		res.type = RTN_LOCAL;
 		goto make_route;
 	}
diff --git a/net/ipv4/netfilter/ipt_rpfilter.c b/net/ipv4/netfilter/ipt_rpfilter.c
index 69f6c713a2b..4bfaedf9b34 100644
--- a/net/ipv4/netfilter/ipt_rpfilter.c
+++ b/net/ipv4/netfilter/ipt_rpfilter.c
@@ -90,7 +90,7 @@ static bool rpfilter_mt(const struct sk_buff *skb, struct xt_action_param *par)
 		if (ipv4_is_zeronet(iph->saddr))
 			return ipv4_is_local_multicast(iph->daddr) ^ invert;
 	}
-	flow.flowi4_iif = dev_net(par->in)->loopback_dev->ifindex;
+	flow.flowi4_iif = LOOPBACK_IFINDEX;
 	flow.daddr = iph->saddr;
 	flow.saddr = rpfilter_get_saddr(iph->daddr);
 	flow.flowi4_oif = 0;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 75cf221285f..e2663f3e180 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2347,7 +2347,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 
 	if (res.type == RTN_LOCAL) {
 		err = fib_validate_source(skb, saddr, daddr, tos,
-					  net->loopback_dev->ifindex,
+					  LOOPBACK_IFINDEX,
 					  dev, &spec_dst, &itag);
 		if (err < 0)
 			goto martian_source_keep_err;
@@ -2674,7 +2674,7 @@ static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
 	orig_saddr = fl4->saddr;
 	orig_oif = fl4->flowi4_oif;
 
-	fl4->flowi4_iif = net->loopback_dev->ifindex;
+	fl4->flowi4_iif = LOOPBACK_IFINDEX;
 	fl4->flowi4_tos = tos & IPTOS_RT_MASK;
 	fl4->flowi4_scope = ((tos & RTO_ONLINK) ?
 			 RT_SCOPE_LINK : RT_SCOPE_UNIVERSE);
@@ -2763,7 +2763,7 @@ static struct rtable *ip_route_output_slow(struct net *net, struct flowi4 *fl4)
 		if (!fl4->daddr)
 			fl4->daddr = fl4->saddr = htonl(INADDR_LOOPBACK);
 		dev_out = net->loopback_dev;
-		fl4->flowi4_oif = net->loopback_dev->ifindex;
+		fl4->flowi4_oif = LOOPBACK_IFINDEX;
 		res.type = RTN_LOCAL;
 		flags |= RTCF_LOCAL;
 		goto make_route;