diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 22eacf423b95..8e95515b74d1 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -3836,10 +3836,13 @@ vm_page_wire(vm_page_t m)
 {
 	u_int old;
 
-	KASSERT(m->object != NULL,
-	    ("vm_page_wire: page %p does not belong to an object", m));
-	if (!vm_page_busied(m) && !vm_object_busied(m->object))
-		VM_OBJECT_ASSERT_LOCKED(m->object);
+#ifdef INVARIANTS
+	if (m->object != NULL) {
+		if (!vm_page_busied(m) && !vm_object_busied(m->object))
+			VM_OBJECT_ASSERT_LOCKED(m->object);
+	} else
+		KASSERT(vm_page_wired(m), ("vm_page_wire: page %p unwired", m));
+#endif
 	KASSERT((m->flags & PG_FICTITIOUS) == 0 ||
 	    VPRC_WIRE_COUNT(m->ref_count) >= 1,
 	    ("vm_page_wire: fictitious page %p has zero wirings", m));