diff --git a/sys/dev/ctau/if_ct.c b/sys/dev/ctau/if_ct.c
index a0441951f510..a05527c71579 100644
--- a/sys/dev/ctau/if_ct.c
+++ b/sys/dev/ctau/if_ct.c
@@ -735,7 +735,8 @@ static int ct_attach (device_t dev)
 		d->pp.pp_if.if_name	= "ct";
 #endif
 		d->pp.pp_if.if_mtu	= PP_MTU;
-		d->pp.pp_if.if_flags	= IFF_POINTOPOINT | IFF_MULTICAST;
+		d->pp.pp_if.if_flags	= IFF_POINTOPOINT | IFF_MULTICAST |
+					  IFF_NEEDSGIANT;
 		d->pp.pp_if.if_ioctl	= ct_sioctl;
 		d->pp.pp_if.if_start	= ct_ifstart;
 		d->pp.pp_if.if_watchdog	= ct_ifwatchdog;
diff --git a/sys/dev/cx/if_cx.c b/sys/dev/cx/if_cx.c
index 7c2e65c436d3..15a0669e6b44 100644
--- a/sys/dev/cx/if_cx.c
+++ b/sys/dev/cx/if_cx.c
@@ -867,7 +867,8 @@ static int cx_attach (device_t dev)
 		d->pp.pp_if.if_name	= "cx";
 #endif
 		d->pp.pp_if.if_mtu	= PP_MTU;
-		d->pp.pp_if.if_flags	= IFF_POINTOPOINT | IFF_MULTICAST;
+		d->pp.pp_if.if_flags	= IFF_POINTOPOINT | IFF_MULTICAST |
+					  IFF_NEEDSGIANT;
 		d->pp.pp_if.if_ioctl	= cx_sioctl;
 		d->pp.pp_if.if_start	= cx_ifstart;
 		d->pp.pp_if.if_watchdog	= cx_ifwatchdog;