diff --git a/UPDATING b/UPDATING
index ed1cf396f514..b45f7724f7ef 100644
--- a/UPDATING
+++ b/UPDATING
@@ -23,6 +23,14 @@ NOTE TO PEOPLE WHO THINK THAT FreeBSD 6.x IS SLOW:
 	developers choose to disable these features on build machines
 	to maximize performance.
 
+20040902:
+	The ifi_epoch change has been reverted because the ABI breakage
+	was too extensive.  If you are running with a kernel/userland
+	containing the initial change (20040830), you should heed the
+	warning about ifconfig incompatibility when upgrading again.
+	With this change, 5.3 and 6.0 ifconfigs and kernels are once
+	again interoperable.
+
 20040830:
 	A new variable, ifi_epoch, has been added to struct if_data
 	which is part if struct ifnet.  This means all network drivers
diff --git a/sys/net/if.c b/sys/net/if.c
index 8097cc1ff510..dce37b935970 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -387,7 +387,6 @@ if_attach(struct ifnet *ifp)
 	TAILQ_INIT(&ifp->if_multiaddrs);
 	knlist_init(&ifp->if_klist, NULL);
 	getmicrotime(&ifp->if_lastchange);
-	getmicrotime(&ifp->if_data.ifi_epoch);
 
 #ifdef MAC
 	mac_init_ifnet(ifp);
diff --git a/sys/net/if.h b/sys/net/if.h
index 95389e60dcf8..8b32fd11f9ad 100644
--- a/sys/net/if.h
+++ b/sys/net/if.h
@@ -104,7 +104,6 @@ struct if_data {
 	u_long	ifi_hwassist;		/* HW offload capabilities */
 	u_long	ifi_unused;		/* XXX was ifi_xmittiming */
 	struct	timeval ifi_lastchange;	/* time of last administrative change */
-	struct	timeval ifi_epoch;	/* time of creation or stat reset */
 };
 
 #define	IFF_UP		0x1		/* interface is up */