diff --git a/hw/bsp/stm32g0/family.c b/hw/bsp/stm32g0/family.c
index 86f2af12e8..67b0b3f1ce 100644
--- a/hw/bsp/stm32g0/family.c
+++ b/hw/bsp/stm32g0/family.c
@@ -43,7 +43,9 @@ void USB_UCPD1_2_IRQHandler(void) {
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM
 //--------------------------------------------------------------------+
+#ifdef UART_DEV
 UART_HandleTypeDef UartHandle;
+#endif
 
 void board_init(void) {
   HAL_Init(); // required for HAL_RCC_Osc TODO check with freeRTOS
@@ -59,8 +61,6 @@ void board_init(void) {
   __HAL_RCC_SYSCFG_CLK_ENABLE();
   __HAL_RCC_PWR_CLK_ENABLE();
 
-  UART_CLK_EN();
-
 #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
@@ -91,6 +91,8 @@ void board_init(void) {
   HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);
 
 #ifdef UART_DEV
+  UART_CLK_EN();
+
   // UART
   GPIO_InitStruct.Pin       = UART_TX_PIN | UART_RX_PIN;
   GPIO_InitStruct.Mode      = GPIO_MODE_AF_PP;
@@ -167,7 +169,6 @@ int board_uart_write(void const *buf, int len) {
 #else
   (void) buf;
   (void) len;
-  (void) UartHandle;
   return 0;
 #endif
 }
diff --git a/hw/bsp/stm32g4/family.c b/hw/bsp/stm32g4/family.c
index d0ef7e5032..49ef86db94 100644
--- a/hw/bsp/stm32g4/family.c
+++ b/hw/bsp/stm32g4/family.c
@@ -57,7 +57,9 @@ void UCPD1_IRQHandler(void) {
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM
 //--------------------------------------------------------------------+
+#ifdef UART_DEV
 UART_HandleTypeDef UartHandle;
+#endif
 
 void board_init(void) {
   HAL_Init();
@@ -71,8 +73,6 @@ void board_init(void) {
   __HAL_RCC_GPIOE_CLK_ENABLE();
   __HAL_RCC_GPIOG_CLK_ENABLE();
 
-  UART_CLK_EN();
-
 #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
@@ -107,6 +107,8 @@ void board_init(void) {
   HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);
 
 #ifdef UART_DEV
+  UART_CLK_EN();
+
   // UART
   memset(&GPIO_InitStruct, 0, sizeof(GPIO_InitStruct));
   GPIO_InitStruct.Pin       = UART_TX_PIN | UART_RX_PIN;
@@ -197,7 +199,6 @@ int board_uart_write(void const *buf, int len) {
 #else
   (void) buf;
   (void) len;
-  (void) UartHandle;
   return 0;
 #endif
 }
diff --git a/hw/bsp/stm32h5/family.c b/hw/bsp/stm32h5/family.c
index efc5bb7b1e..26ba34ac3a 100644
--- a/hw/bsp/stm32h5/family.c
+++ b/hw/bsp/stm32h5/family.c
@@ -58,7 +58,9 @@ void USB_DRD_FS_IRQHandler(void) {
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM
 //--------------------------------------------------------------------+
+#ifdef UART_DEV
 UART_HandleTypeDef UartHandle;
+#endif
 
 void board_init(void) {
   HAL_Init(); // required for HAL_RCC_Osc TODO check with freeRTOS
@@ -82,8 +84,6 @@ void board_init(void) {
   __HAL_RCC_GPIOI_CLK_ENABLE();
   #endif
 
-  UART_CLK_EN();
-
   #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
@@ -114,6 +114,8 @@ void board_init(void) {
   HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);
 
   #ifdef UART_DEV
+  UART_CLK_EN();
+
   // UART
   GPIO_InitStruct.Pin = UART_TX_PIN | UART_RX_PIN;
   GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
@@ -192,7 +194,6 @@ int board_uart_write(void const* buf, int len) {
   #else
   (void) buf;
   (void) len;
-  (void) UartHandle;
   return 0;
   #endif
 }
diff --git a/hw/bsp/stm32wb/family.c b/hw/bsp/stm32wb/family.c
index 43e1345c80..ba37b7cc34 100644
--- a/hw/bsp/stm32wb/family.c
+++ b/hw/bsp/stm32wb/family.c
@@ -46,7 +46,9 @@ void USB_LP_IRQHandler(void) {
 //--------------------------------------------------------------------+
 // MACRO TYPEDEF CONSTANT ENUM
 //--------------------------------------------------------------------+
+#ifdef UART_DEV
 UART_HandleTypeDef UartHandle;
+#endif
 
 void board_init(void) {
   board_clock_init();
@@ -58,8 +60,6 @@ void board_init(void) {
   __HAL_RCC_GPIOD_CLK_ENABLE();
   __HAL_RCC_GPIOE_CLK_ENABLE();
 
-  UART_CLK_EN();
-
 #if CFG_TUSB_OS == OPT_OS_NONE
   // 1ms tick timer
   SysTick_Config(SystemCoreClock / 1000);
@@ -102,6 +102,8 @@ void board_init(void) {
   HAL_GPIO_Init(BUTTON_PORT, &GPIO_InitStruct);
 
 #ifdef UART_DEV
+  UART_CLK_EN();
+
   // UART
   GPIO_InitStruct.Pin = UART_TX_PIN | UART_RX_PIN;
   GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
@@ -159,7 +161,7 @@ int board_uart_write(void const* buf, int len) {
   HAL_UART_Transmit(&UartHandle, (uint8_t*) (uintptr_t) buf, len, 0xffff);
   return len;
 #else
-  (void) buf; (void) len; (void) UartHandle;
+  (void) buf; (void) len;
   return 0;
 #endif
 }