diff --git a/bin/varnishd/cache/cache_vrt.c b/bin/varnishd/cache/cache_vrt.c
index e4c0261f87..b0f5619558 100644
--- a/bin/varnishd/cache/cache_vrt.c
+++ b/bin/varnishd/cache/cache_vrt.c
@@ -650,8 +650,7 @@ VRT_VSM_Cluster_Destroy(VRT_CTX, struct vsmw_cluster **vcp)
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	AN(vcp);
-	AN(*vcp);
-	*vcp = NULL;
+	VSMW_DestroyCluster(heritage.proc_vsmw, vcp);
 }
 
 /*--------------------------------------------------------------------
diff --git a/bin/varnishd/common/common_vsmw.c b/bin/varnishd/common/common_vsmw.c
index 8e55aebe25..beb6fbd3b5 100644
--- a/bin/varnishd/common/common_vsmw.c
+++ b/bin/varnishd/common/common_vsmw.c
@@ -72,6 +72,7 @@ struct vsmw_cluster {
 #define VSMW_CLUSTER_MAGIC		0x28b74c00
 
 	VTAILQ_ENTRY(vsmw_cluster)	list;
+	struct vsmwseg			*cseg;
 	char				*fn;
 	size_t				len;
 	void				*ptr;
@@ -182,9 +183,6 @@ vsmw_delseg(struct vsmw *vsmw, struct vsmwseg *seg, int fixidx)
 	CHECK_OBJ_NOTNULL(vsmw, VSMW_MAGIC);
 	CHECK_OBJ_NOTNULL(seg, VSMWSEG_MAGIC);
 
-	if (!--seg->cluster->refs)
-		VSMW_DestroyCluster(vsmw, &seg->cluster);
-
 	VTAILQ_REMOVE(&vsmw->segs, seg, list);
 	REPLACE(seg->class, NULL);
 	REPLACE(seg->id, NULL);
@@ -208,8 +206,8 @@ vsmw_delseg(struct vsmw *vsmw, struct vsmwseg *seg, int fixidx)
 
 /*--------------------------------------------------------------------*/
 
-struct vsmw_cluster *
-VSMW_NewCluster(struct vsmw *vsmw, size_t len, const char *pfx)
+static struct vsmw_cluster *
+vsmw_newcluster(struct vsmw *vsmw, size_t len, const char *pfx)
 {
 	struct vsmw_cluster *vc;
 	int fd;
@@ -245,6 +243,26 @@ VSMW_NewCluster(struct vsmw *vsmw, size_t len, const char *pfx)
 	return (vc);
 }
 
+struct vsmw_cluster *
+VSMW_NewCluster(struct vsmw *vsmw, size_t len, const char *pfx)
+{
+	struct vsmw_cluster *vc;
+	struct vsmwseg *seg;
+
+	vc = vsmw_newcluster(vsmw, len, pfx);
+
+	ALLOC_OBJ(seg, VSMWSEG_MAGIC);
+	AN(seg);
+	vc->cseg = seg;
+	seg->len = len;
+	seg->cluster = vc;
+	REPLACE(seg->class, "");
+	REPLACE(seg->id, "");
+	vsmw_addseg(vsmw, seg);
+
+	return (vc);
+}
+
 void
 VSMW_DestroyCluster(struct vsmw *vsmw, struct vsmw_cluster **vcp)
 {
@@ -255,10 +273,22 @@ VSMW_DestroyCluster(struct vsmw *vsmw, struct vsmw_cluster **vcp)
 	vc = *vcp;
 	*vcp = NULL;
 	CHECK_OBJ_NOTNULL(vc, VSMW_CLUSTER_MAGIC);
-	AZ(vc->refs);
 
+	if (vc->cseg != NULL) {
+		/*
+		 * Backends go on the cool list, so the VGC cluster is
+		 * destroyed before they are.  Solve this by turning the
+		 * cluster into an anonymous cluster which dies with the
+		 * refcount on it.
+		 */
+		vsmw_delseg(vsmw, vc->cseg, 1);
+		vc->cseg = NULL;
+		if (vc->refs > 0)
+			return;
+	}
 	AZ(munmap(vc->ptr, vc->len));
 
+	AZ(vc->refs);
 	VTAILQ_REMOVE(&vsmw->clusters, vc, list);
 	if (unlinkat(vsmw->vdirfd, vc->fn, 0))
 		assert (errno == ENOENT);
@@ -289,7 +319,7 @@ VSMW_Allocv(struct vsmw *vsmw, struct vsmw_cluster *vc,
 	REPLACE(seg->id, VSB_data(vsmw->vsb));
 
 	if (vc == NULL)
-		vc = VSMW_NewCluster(vsmw, seg->len, class);
+		vc = vsmw_newcluster(vsmw, seg->len, class);
 	AN(vc);
 	vc->refs++;
 
@@ -334,6 +364,10 @@ VSMW_Free(struct vsmw *vsmw, void **pp)
 		if (seg->ptr == p)
 			break;
 	AN(seg);
+
+	if (!--seg->cluster->refs && seg->cluster->cseg == NULL)
+		VSMW_DestroyCluster(vsmw, &seg->cluster);
+
 	vsmw_delseg(vsmw, seg, 1);
 }
 
diff --git a/bin/varnishd/flint.lnt b/bin/varnishd/flint.lnt
index e31a0d58f8..923b7028e4 100644
--- a/bin/varnishd/flint.lnt
+++ b/bin/varnishd/flint.lnt
@@ -96,6 +96,7 @@
 
 +libh mgt_event.h
 
+-sem(vsmw_addseg, custodial(2))
 -sem(BAN_Free, custodial(1))
 -sem(EXP_Inject, custodial(1))
 -sem(HSH_Insert, custodial(3))
diff --git a/lib/libvarnishapi/vsm.c b/lib/libvarnishapi/vsm.c
index be15a14ec1..0766e539e6 100644
--- a/lib/libvarnishapi/vsm.c
+++ b/lib/libvarnishapi/vsm.c
@@ -418,9 +418,7 @@ vsm_refresh_set2(struct vsm *vd, struct vsm_set *vs, struct vsb *vsb)
 		return (retval|VSM_NUKE_ALL);
 
 	/*
-	 * Examine the ident line
-	 * XXX: for now ignore that one of the ID's is a pid which could
-	 * XXX: be kill(pid,0)'ed for more rapid abandonment detection.
+	 * First line is ident comment
 	 */
 	i = sscanf(VSB_data(vsb), "# %ju %ju\n%n", &id1, &id2, &ac);
 	if (i != 2) {
@@ -445,7 +443,7 @@ vsm_refresh_set2(struct vsm *vd, struct vsm_set *vs, struct vsb *vsb)
 		vg->markscan = 0;
 
 	/*
-	 * Efficient comparison walking the two lists side-by-side is ok because
+	 * Efficient comparison by walking the two lists side-by-side because
 	 * segment inserts always happen at the tail (VSMW_Allocv()). So, as
 	 * soon as vg is exhausted, we only insert.
 	 *
@@ -465,13 +463,17 @@ vsm_refresh_set2(struct vsm *vd, struct vsm_set *vs, struct vsb *vsb)
 		av = VAV_Parse(p, &ac, 0);
 		p = e + 1;
 
-		if (av[0] != NULL || ac < 5 || ac > 6) {
+		if (av[0] != NULL || ac < 4 || ac > 6) {
 			(void)(vsm_diag(vd,
 			    "vsm_refresh_set2: bad index (%d/%s)",
 			    ac, av[0]));
 			VAV_Free(av);
 			break;
 		}
+		if (ac == 4) {
+			VAV_Free(av);
+			continue;
+		}
 
 		if (vg == NULL) {
 			ALLOC_OBJ(vg2, VSM_SEG_MAGIC);
diff --git a/lib/libvcc/vcc_backend.c b/lib/libvcc/vcc_backend.c
index 43f9eea577..a5a433f327 100644
--- a/lib/libvcc/vcc_backend.c
+++ b/lib/libvcc/vcc_backend.c
@@ -506,5 +506,5 @@ vcc_Backend_Init(struct vcc *tl)
 	VSB_printf(ifp->ini, "\tvsc_cluster = VRT_VSM_Cluster_New(ctx,\n"
 	    "\t    ndirector * VRT_backend_vsm_need(ctx));\n");
 	VSB_printf(ifp->ini, "\tif (vsc_cluster == 0)\n\t\treturn(1);");
-	VSB_printf(ifp->fin, "\tVRT_VSM_Cluster_Destroy(ctx, &vsc_cluster);");
+	VSB_printf(ifp->fin, "\t\tVRT_VSM_Cluster_Destroy(ctx, &vsc_cluster);");
 }