diff --git a/zephcore/boards/nrf52840/xiao_nrf52840/board.conf b/zephcore/boards/nrf52840/xiao_nrf52840/board.conf
index 17ec807..b7c978b 100644
--- a/zephcore/boards/nrf52840/xiao_nrf52840/board.conf
+++ b/zephcore/boards/nrf52840/xiao_nrf52840/board.conf
@@ -8,3 +8,9 @@ CONFIG_BT_DIS_MODEL_NUMBER_STR="Seeed XIAO nRF52840"
 CONFIG_ZEPHCORE_SD_FWID=0x0123
 
 CONFIG_ZEPHCORE_MAX_CONTACTS=510
+
+# Default debug (logging.conf) sends LOG_* to RTT only. Plain XIAO is usually
+# flashed/debugged over USB without an SWD J-Link — enable UART backend so
+# LOG_* appears on the CDC ACM serial port (same as zephyr,console).
+# RTT remains enabled for J-Link; use DROP mode (see zephcore_common.conf).
+CONFIG_LOG_BACKEND_UART=y