diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -892,6 +892,9 @@
 	    ("%s: page %p is inconsistent", __func__, p));
 	p->object = NULL;
 	if (vm_page_drop(p, VPRC_OBJREF) == VPRC_OBJREF) {
+		KASSERT((object->flags & OBJ_UNMANAGED) != 0 ||
+		    vm_page_astate_load(p).queue != PQ_NONE,
+		    ("%s: page %p does not belong to a queue", __func__, p));
 		VM_CNT_INC(v_pfree);
 		vm_page_free(p);
 	}