Missed doc change in #850
diff --git a/src/rp2_common/hardware_gpio/include/hardware/gpio.h b/src/rp2_common/hardware_gpio/include/hardware/gpio.h
index 09a9b96..7138de5 100644
--- a/src/rp2_common/hardware_gpio/include/hardware/gpio.h
+++ b/src/rp2_common/hardware_gpio/include/hardware/gpio.h
@@ -615,6 +615,8 @@
*
* This method removes such a callback, and enables the "default" callback for the specified GPIOs.
*
+ * \note You should always use the same gpio_mask as you used when you added the raw IRQ handler.
+ *
* @param gpio_mask a bit mask of the GPIO numbers that will now be passed to the default callback for this core
* @param handler the handler to remove from the list of GPIO IRQ handlers for this core
*/
