diff --git a/lib/ftl/ftl_rwb.c b/lib/ftl/ftl_rwb.c
index 5ef26a11a..e8979f159 100644
--- a/lib/ftl/ftl_rwb.c
+++ b/lib/ftl/ftl_rwb.c
@@ -178,7 +178,7 @@ ftl_rwb_init(const struct spdk_ftl_conf *conf, size_t xfer_size, size_t md_size)
 {
 	struct ftl_rwb *rwb;
 	struct ftl_rwb_batch *batch;
-	size_t ring_size, i;
+	size_t i;
 
 	rwb = calloc(1, sizeof(*rwb));
 	if (!rwb) {
@@ -191,14 +191,13 @@ ftl_rwb_init(const struct spdk_ftl_conf *conf, size_t xfer_size, size_t md_size)
 	rwb->md_size = md_size;
 	rwb->num_batches = conf->rwb_size / (FTL_BLOCK_SIZE * xfer_size);
 
-	ring_size = spdk_align32pow2(rwb->num_batches);
-
 	rwb->batches = calloc(rwb->num_batches, sizeof(*rwb->batches));
 	if (!rwb->batches) {
 		goto error;
 	}
 
-	rwb->submit_queue = spdk_ring_create(SPDK_RING_TYPE_MP_SC, ring_size,
+	rwb->submit_queue = spdk_ring_create(SPDK_RING_TYPE_MP_SC,
+					     spdk_align32pow2(rwb->num_batches + 1),
 					     SPDK_ENV_SOCKET_ID_ANY);
 	if (!rwb->submit_queue) {
 		SPDK_ERRLOG("Failed to create submission queue\n");