diff --git a/sys/net/if.c b/sys/net/if.c
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -273,6 +273,7 @@
  */
 static void	if_attachdomain(void *);
 static void	if_attachdomain1(struct ifnet *);
+static void	if_detachdomain1(struct ifnet *);
 static int	ifconf(u_long, caddr_t);
 static void	if_input_default(struct ifnet *, struct mbuf *);
 static int	if_requestencap_default(struct ifnet *, struct if_encap_req *);
@@ -1003,6 +1004,32 @@
 	}
 }
 
+static void
+if_detachdomain1(struct ifnet *ifp)
+{
+	int i;
+	struct domain *dp;
+
+	/*
+	 * We cannot hold the lock over dom_ifdetach calls as they might
+	 * sleep, for example trying to drain a callout, thus open up the
+	 * theoretical race with re-attaching.
+	 */
+	IF_AFDATA_LOCK(ifp);
+	i = ifp->if_afdata_initialized;
+	ifp->if_afdata_initialized = 0;
+	IF_AFDATA_UNLOCK(ifp);
+	if (i == 0)
+		return;
+	SLIST_FOREACH(dp, &domains, dom_next) {
+		if (dp->dom_ifdetach && ifp->if_afdata[dp->dom_family]) {
+			(*dp->dom_ifdetach)(ifp,
+			    ifp->if_afdata[dp->dom_family]);
+			ifp->if_afdata[dp->dom_family] = NULL;
+		}
+	}
+}
+
 /*
  * Remove any unicast or broadcast network addresses from an interface.
  */
@@ -1115,8 +1142,6 @@
 if_detach_internal(struct ifnet *ifp, bool vmove)
 {
 	struct ifaddr *ifa;
-	int i;
-	struct domain *dp;
 #ifdef VIMAGE
 	bool shutdown;
 
@@ -1259,24 +1284,7 @@
 #ifdef VIMAGE
 finish_vnet_shutdown:
 #endif
-	/*
-	 * We cannot hold the lock over dom_ifdetach calls as they might
-	 * sleep, for example trying to drain a callout, thus open up the
-	 * theoretical race with re-attaching.
-	 */
-	IF_AFDATA_LOCK(ifp);
-	i = ifp->if_afdata_initialized;
-	ifp->if_afdata_initialized = 0;
-	IF_AFDATA_UNLOCK(ifp);
-	if (i == 0)
-		return;
-	SLIST_FOREACH(dp, &domains, dom_next) {
-		if (dp->dom_ifdetach && ifp->if_afdata[dp->dom_family]) {
-			(*dp->dom_ifdetach)(ifp,
-			    ifp->if_afdata[dp->dom_family]);
-			ifp->if_afdata[dp->dom_family] = NULL;
-		}
-	}
+	if_detachdomain1(ifp);
 }
 
 #ifdef VIMAGE