diff --git a/components/esp_event/include/esp_event.h b/components/esp_event/include/esp_event.h
index 6bed74d195..ebef99ae56 100644
--- a/components/esp_event/include/esp_event.h
+++ b/components/esp_event/include/esp_event.h
@@ -199,6 +199,8 @@ esp_err_t esp_event_handler_register_with(esp_event_loop_handle_t event_loop,
  * @note the event loop library does not maintain a copy of event_handler_arg, therefore the user should
  * ensure that event_handler_arg still points to a valid location by the time the handler gets called
  *
+ * @note Calling this function with instance set to NULL is equivalent to calling esp_event_handler_register_with.
+ *
  * @return
  *  - ESP_OK: Success
  *  - ESP_ERR_NO_MEM: Cannot allocate memory for the handler
@@ -232,6 +234,8 @@ esp_err_t esp_event_handler_instance_register_with(esp_event_loop_handle_t event
  * @note the event loop library does not maintain a copy of event_handler_arg, therefore the user should
  * ensure that event_handler_arg still points to a valid location by the time the handler gets called
  *
+ * @note Calling this function with instance set to NULL is equivalent to calling esp_event_handler_register.
+ *
  * @return
  *  - ESP_OK: Success
  *  - ESP_ERR_NO_MEM: Cannot allocate memory for the handler