diff --git a/sys/dev/nvmf/host/nvmf_ns.c b/sys/dev/nvmf/host/nvmf_ns.c
--- a/sys/dev/nvmf/host/nvmf_ns.c
+++ b/sys/dev/nvmf/host/nvmf_ns.c
@@ -313,7 +313,7 @@
 
 struct nvmf_namespace *
 nvmf_init_ns(struct nvmf_softc *sc, uint32_t id,
-    struct nvme_namespace_data *data)
+    const struct nvme_namespace_data *data)
 {
 	struct make_dev_args mda;
 	struct nvmf_namespace *ns;
@@ -454,7 +454,8 @@
 }
 
 bool
-nvmf_update_ns(struct nvmf_namespace *ns, struct nvme_namespace_data *data)
+nvmf_update_ns(struct nvmf_namespace *ns,
+    const struct nvme_namespace_data *data)
 {
 	uint8_t lbads, lbaf;
 
diff --git a/sys/dev/nvmf/host/nvmf_var.h b/sys/dev/nvmf/host/nvmf_var.h
--- a/sys/dev/nvmf/host/nvmf_var.h
+++ b/sys/dev/nvmf/host/nvmf_var.h
@@ -180,12 +180,12 @@
 
 /* nvmf_ns.c */
 struct nvmf_namespace *nvmf_init_ns(struct nvmf_softc *sc, uint32_t id,
-    struct nvme_namespace_data *data);
+    const struct nvme_namespace_data *data);
 void	nvmf_disconnect_ns(struct nvmf_namespace *ns);
 void	nvmf_reconnect_ns(struct nvmf_namespace *ns);
 void	nvmf_destroy_ns(struct nvmf_namespace *ns);
 bool	nvmf_update_ns(struct nvmf_namespace *ns,
-    struct nvme_namespace_data *data);
+    const struct nvme_namespace_data *data);
 
 /* nvmf_qpair.c */
 struct nvmf_host_qpair *nvmf_init_qp(struct nvmf_softc *sc,