diff --git a/test/unit/lib/nvme/nvme_ctrlr.c/nvme_ctrlr_ut.c b/test/unit/lib/nvme/nvme_ctrlr.c/nvme_ctrlr_ut.c
index 33d1aaa74..89fcdee30 100644
--- a/test/unit/lib/nvme/nvme_ctrlr.c/nvme_ctrlr_ut.c
+++ b/test/unit/lib/nvme/nvme_ctrlr.c/nvme_ctrlr_ut.c
@@ -2127,7 +2127,7 @@ test_nvme_ctrlr_test_active_ns(void)
 		nsid = spdk_nvme_ctrlr_get_next_active_ns(&ctrlr, nsid);
 		CU_ASSERT(nsid == 0);
 
-		memset(ctrlr.active_ns_list, 0, ctrlr.num_ns);
+		memset(ctrlr.active_ns_list, 0, sizeof(uint32_t) * ctrlr.num_ns);
 		for (nsid = 0; nsid < ctrlr.num_ns; nsid++) {
 			ctrlr.active_ns_list[nsid] = nsid + 1;
 		}