diff --git a/lib/nvmf/subsystem.c b/lib/nvmf/subsystem.c
index 3d56bdf79..e68a6fa93 100644
--- a/lib/nvmf/subsystem.c
+++ b/lib/nvmf/subsystem.c
@@ -328,6 +328,11 @@ spdk_nvmf_subsystem_add_ns(struct spdk_nvmf_subsystem *subsystem, struct spdk_bd
 	uint32_t i;
 	int rc;
 
+	if (nsid == SPDK_NVME_GLOBAL_NS_TAG) {
+		SPDK_ERRLOG("Invalid NSID %" PRIu32 "\n", nsid);
+		return 0;
+	}
+
 	if (nsid > subsystem->max_nsid ||
 	    (nsid == 0 && subsystem->num_allocated_nsid == subsystem->max_nsid)) {
 		struct spdk_nvmf_ns *new_ns_array;
diff --git a/test/unit/lib/nvmf/subsystem.c/subsystem_ut.c b/test/unit/lib/nvmf/subsystem.c/subsystem_ut.c
index abda3e2ec..1148e28de 100644
--- a/test/unit/lib/nvmf/subsystem.c/subsystem_ut.c
+++ b/test/unit/lib/nvmf/subsystem.c/subsystem_ut.c
@@ -189,6 +189,11 @@ test_spdk_nvmf_subsystem_add_ns(void)
 	CU_ASSERT(nsid == 0);
 	CU_ASSERT(subsystem.max_nsid == 5);
 
+	/* Request 0xFFFFFFFF (invalid NSID, reserved for broadcast) */
+	nsid = spdk_nvmf_subsystem_add_ns(&subsystem, &bdev2, 0xFFFFFFFF);
+	CU_ASSERT(nsid == 0);
+	CU_ASSERT(subsystem.max_nsid == 5);
+
 	free(subsystem.ns);
 }