diff --git a/include/spdk/nbd.h b/include/spdk/nbd.h
index 584dd0652..d987c1c4b 100644
--- a/include/spdk/nbd.h
+++ b/include/spdk/nbd.h
@@ -81,9 +81,8 @@ void spdk_nbd_stop(struct spdk_nbd_disk *nbd);
  * Write NBD subsystem configuration into provided JSON context.
  *
  * \param w JSON write context
- * \param done_ev call this event when done.
  */
-void spdk_nbd_write_config_json(struct spdk_json_write_ctx *w, struct spdk_event *done_ev);
+void spdk_nbd_write_config_json(struct spdk_json_write_ctx *w);
 
 #ifdef __cplusplus
 }
diff --git a/lib/event/subsystems/nbd/nbd.c b/lib/event/subsystems/nbd/nbd.c
index 767364462..a943eb82f 100644
--- a/lib/event/subsystems/nbd/nbd.c
+++ b/lib/event/subsystems/nbd/nbd.c
@@ -54,12 +54,20 @@ spdk_nbd_subsystem_fini(void)
 	spdk_subsystem_fini_next();
 }
 
+static void
+spdk_nbd_subsystem_write_config_json(struct spdk_json_write_ctx *w,
+				     struct spdk_event *done_ev)
+{
+	spdk_nbd_write_config_json(w);
+	spdk_event_call(done_ev);
+}
+
 static struct spdk_subsystem g_spdk_subsystem_nbd = {
 	.name = "nbd",
 	.init = spdk_nbd_subsystem_init,
 	.fini = spdk_nbd_subsystem_fini,
 	.config = NULL,
-	.write_config_json = spdk_nbd_write_config_json,
+	.write_config_json = spdk_nbd_subsystem_write_config_json,
 };
 
 SPDK_SUBSYSTEM_REGISTER(g_spdk_subsystem_nbd);
diff --git a/lib/nbd/nbd.c b/lib/nbd/nbd.c
index ad635ff4d..fc7726a44 100644
--- a/lib/nbd/nbd.c
+++ b/lib/nbd/nbd.c
@@ -211,7 +211,7 @@ spdk_nbd_disk_get_bdev_name(struct spdk_nbd_disk *nbd)
 }
 
 void
-spdk_nbd_write_config_json(struct spdk_json_write_ctx *w, struct spdk_event *done_ev)
+spdk_nbd_write_config_json(struct spdk_json_write_ctx *w)
 {
 	struct spdk_nbd_disk *nbd;
 
@@ -231,7 +231,6 @@ spdk_nbd_write_config_json(struct spdk_json_write_ctx *w, struct spdk_event *don
 	}
 
 	spdk_json_write_array_end(w);
-	spdk_event_call(done_ev);
 }
 
 void