diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 8817f8a..de5809a 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1653,7 +1653,7 @@ static int select_pmem_id(struct nd_region *nd_region, u8 *pmem_id)
 		u64 hw_start, hw_end, pmem_start, pmem_end;
 		struct nd_label_ent *label_ent;
 
-		WARN_ON(!mutex_is_locked(&nd_mapping->lock));
+		lockdep_assert_held(&nd_mapping->lock);
 		list_for_each_entry(label_ent, &nd_mapping->labels, list) {
 			nd_label = label_ent->label;
 			if (!nd_label)