diff --git a/include/uapi/linux/gpio.h b/include/uapi/linux/gpio.h
index f7cb8ae87df7..5515b718886e 100644
--- a/include/uapi/linux/gpio.h
+++ b/include/uapi/linux/gpio.h
@@ -218,7 +218,7 @@ struct gpio_v2_line_request {
  * gpio_v2_line_flag, such as %GPIO_V2_LINE_FLAG_ACTIVE_LOW,
  * %GPIO_V2_LINE_FLAG_OUTPUT etc, added together
  * @attrs: the configuration attributes associated with the line
- * @padding: reserved for future use
+ * @padding: reserved for future use, must be zero filled
  */
 struct gpio_v2_line_info {
 	char name[GPIO_MAX_NAME_SIZE];