diff --git a/examples/stm32/nucleo-f429zi-baremetal/Makefile b/examples/stm32/nucleo-f429zi-baremetal/Makefile
index 98e3787b..2d2456ee 100644
--- a/examples/stm32/nucleo-f429zi-baremetal/Makefile
+++ b/examples/stm32/nucleo-f429zi-baremetal/Makefile
@@ -23,7 +23,8 @@ flash: firmware.bin
 
 # Requires env variable VCON_API_KEY set
 DEVICE_URL ?= https://dash.vcon.io/api/v3/devices/2
-test: update
+test:	EXTRA_CFLAGS += -DUART_DEBUG=UART1
+test:	update
 	curl --fail -su :$(VCON_API_KEY) $(DEVICE_URL)/tx?t=5 | tee /tmp/output.txt
 	grep 'Ethernet: up' /tmp/output.txt
 	grep 'MQTT connected' /tmp/output.txt
diff --git a/examples/stm32/nucleo-f429zi-baremetal/main.c b/examples/stm32/nucleo-f429zi-baremetal/main.c
index ce6e8382..c8bd14e8 100644
--- a/examples/stm32/nucleo-f429zi-baremetal/main.c
+++ b/examples/stm32/nucleo-f429zi-baremetal/main.c
@@ -44,7 +44,7 @@ int main(void) {
   gpio_output(LED2);                   // Setup blue LED
   gpio_input(BTN1);                    // Set button to input
   irq_exti_attach(BTN1);               // Attach BTN1 to exti
-  uart_init(UART1, 115200);            // Initialise debug printf
+  uart_init(UART_DEBUG, 115200);       // Initialise debug printf
 
   MG_INFO(("Starting, CPU freq %g MHz", (double) SYS_FREQUENCY / 1000000));
 
diff --git a/examples/stm32/nucleo-f429zi-baremetal/mcu.h b/examples/stm32/nucleo-f429zi-baremetal/mcu.h
index 8cda5c45..57ed552b 100644
--- a/examples/stm32/nucleo-f429zi-baremetal/mcu.h
+++ b/examples/stm32/nucleo-f429zi-baremetal/mcu.h
@@ -157,6 +157,10 @@ struct uart {
 #define UART2 ((struct uart *) 0x40004400)
 #define UART3 ((struct uart *) 0x40004800)
 
+#ifndef UART_DEBUG
+#define UART_DEBUG UART3
+#endif
+
 static inline void uart_init(struct uart *uart, unsigned long baud) {
   // https://www.st.com/resource/en/datasheet/stm32f429zi.pdf
   uint8_t af = 7;           // Alternate function