diff --git a/examples/openthread/ot_br/main/esp_ot_br.c b/examples/openthread/ot_br/main/esp_ot_br.c
index f0b31fa0b0..18dea1cec4 100644
--- a/examples/openthread/ot_br/main/esp_ot_br.c
+++ b/examples/openthread/ot_br/main/esp_ot_br.c
@@ -105,8 +105,10 @@ void app_main(void)
     // * task queue
     // * border router
     esp_vfs_eventfd_config_t eventfd_config = {
-#if CONFIG_OPENTHREAD_RADIO_NATIVE
+#if CONFIG_OPENTHREAD_RADIO_NATIVE || CONFIG_OPENTHREAD_RADIO_SPINEL_SPI
         // * radio driver (A native radio device needs a eventfd for radio driver.)
+        // * SpiSpinelInterface (The Spi Spinel Interface needs a eventfd.)
+        // The above will not exist at the same time.
         .max_fds = 4,
 #else
         .max_fds = 3,