diff --git a/lib/nvmf/ctrlr_bdev.c b/lib/nvmf/ctrlr_bdev.c
index 91d940c20..9e755fa1d 100644
--- a/lib/nvmf/ctrlr_bdev.c
+++ b/lib/nvmf/ctrlr_bdev.c
@@ -150,7 +150,7 @@ nvmf_bdev_ctrlr_identify_ns(struct spdk_nvmf_ns *ns, struct spdk_nvme_ns_data *n
 	nsdata->nuse = num_blocks;
 	nsdata->nlbaf = 0;
 	nsdata->flbas.format = 0;
-	nsdata->nacwu = spdk_bdev_get_acwu(bdev);
+	nsdata->nacwu = spdk_bdev_get_acwu(bdev) - 1; /* nacwu is 0-based */
 	if (!dif_insert_or_strip) {
 		nsdata->lbaf[0].ms = spdk_bdev_get_md_size(bdev);
 		nsdata->lbaf[0].lbads = spdk_u32log2(spdk_bdev_get_block_size(bdev));
diff --git a/test/unit/lib/nvmf/ctrlr_bdev.c/ctrlr_bdev_ut.c b/test/unit/lib/nvmf/ctrlr_bdev.c/ctrlr_bdev_ut.c
index 235ce7115..1a06aa56a 100644
--- a/test/unit/lib/nvmf/ctrlr_bdev.c/ctrlr_bdev_ut.c
+++ b/test/unit/lib/nvmf/ctrlr_bdev.c/ctrlr_bdev_ut.c
@@ -487,7 +487,7 @@ test_nvmf_bdev_ctrlr_identify_ns(void)
 	memcpy(ns.opts.eui64, eui64, 8);
 
 	bdev.blockcnt = 10;
-	bdev.acwu = 0;
+	bdev.acwu = 1;
 	bdev.md_len = 512;
 	bdev.dif_type = SPDK_DIF_TYPE1;
 	bdev.blocklen = 4096;