diff --git a/machine/arm/stm32l4xx/interface/uart.c b/machine/arm/stm32l4xx/interface/uart.c
index 8047d94..abf4621 100644
--- a/machine/arm/stm32l4xx/interface/uart.c
+++ b/machine/arm/stm32l4xx/interface/uart.c
@@ -1,5 +1,9 @@
 
 #include "lib.h"
+#include "stm32l4xx.h"
+#include "stm32l4xx_hal_gpio.h"
+#include "stm32l4xx_hal_rcc.h"
+#include "stm32l4xx_hal_rcc_ex.h"
 
 #include <stm32l4xx_hal.h>
 
@@ -50,5 +54,31 @@ void HAL_UART_MspInit(UART_HandleTypeDef *huart) {
     HAL_PWREx_EnableVddIO2();
     __HAL_RCC_GPIOG_CLK_ENABLE();
     HAL_GPIO_Init(GPIOG, &GPIO_InitStruct);
+  } else if (huart->Instance == UART5) {
+
+    RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
+    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_UART5;
+    PeriphClkInit.Uart5ClockSelection = RCC_UART5CLKSOURCE_PCLK1;
+    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK) {
+      return;
+    }
+
+    __HAL_RCC_UART5_CLK_ENABLE();
+
+    // Enable GPIO clocks
+    HAL_PWREx_EnableVddIO2();
+    __HAL_RCC_GPIOC_CLK_ENABLE();
+    __HAL_RCC_GPIOD_CLK_ENABLE();
+
+    GPIO_InitTypeDef GPIO_InitStruct = {0};
+    GPIO_InitStruct.Pin = GPIO_PIN_12; // PC12 == UART5_TX
+    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
+    GPIO_InitStruct.Pull = GPIO_NOPULL;
+    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
+    GPIO_InitStruct.Alternate = GPIO_AF8_UART5;
+    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);
+    // PD2 == UART5_RX
+    GPIO_InitStruct.Pin = GPIO_PIN_2;
+    HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
   }
-}
\ No newline at end of file
+}
diff --git a/options.toml b/options.toml
index d595d37..985e288 100644
--- a/options.toml
+++ b/options.toml
@@ -13,7 +13,7 @@ type = "Boolean"
 [debug.uart]
 name = "Debug UART"
 description = "Select the UART peripheral to use for debug output."
-type = { type = "String", allowed_values = ["LPUART1"] }
+type = { type = "String", allowed_values = ["LPUART1", "UART5"] }
 default = "LPUART1"
 
 [tuning]
@@ -36,4 +36,4 @@ default = 8192
 name = "Application Stack Size"
 description = "Sets the size of the stack for the init application. This must be less than the application memory size."
 type = { type = "Integer", min = 0 }
-default = 2048
\ No newline at end of file
+default = 2048