diff --git a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F437xG/TARGET_UBLOX_C030/system_stm32f4xx.c b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F437xG/TARGET_UBLOX_C030/system_stm32f4xx.c
index 6258433392..92c80d9f5a 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F437xG/TARGET_UBLOX_C030/system_stm32f4xx.c
+++ b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F437xG/TARGET_UBLOX_C030/system_stm32f4xx.c
@@ -21,20 +21,20 @@
   *                                 during program execution.
   *
   * This file configures the system clock as follows:
-  *--------------------------------------------------------------------------------------
-  * System clock source                | PLL_HSE_XTAL           | PLL_HSE_XTAL           
-  *                                    | (external 8 MHz clock) | (external 8 MHz clock) 
-  *--------------------------------------------------------------------------------------
-  * SYSCLK(MHz)                        | 168                    | 84                    
-  *--------------------------------------------------------------------------------------
-  * AHBCLK (MHz)                       | 168                    | 84                   
-  *--------------------------------------------------------------------------------------
-  * APB1CLK (MHz)                      | 42                     | 42                     
-  *--------------------------------------------------------------------------------------
-  * APB2CLK (MHz)                      | 84                     | 84                     
-  *--------------------------------------------------------------------------------------
-  * USB capable (48 MHz precise clock) | YES                    | YES                     
-  *--------------------------------------------------------------------------------------
+  *----------------------------------------------------------------------------------------------------------------------------------------
+  * System clock source                | PLL_HSE_XTAL           | PLL_HSE_XTAL           | PLL_HSE_XTAL           | PLL_HSE_XTAL
+  *                                    | (external 8 MHz clock) | (external 8 MHz clock) | (external 12 MHz clock)| (external 12 MHz clock)
+  *----------------------------------------------------------------------------------------------------------------------------------------
+  * SYSCLK(MHz)                        | 168                    | 84                     | 168                    | 84
+  *----------------------------------------------------------------------------------------------------------------------------------------
+  * AHBCLK (MHz)                       | 168                    | 84                     | 168                    | 84
+  *----------------------------------------------------------------------------------------------------------------------------------------
+  * APB1CLK (MHz)                      | 42                     | 42                     | 42                     | 42
+  *----------------------------------------------------------------------------------------------------------------------------------------
+  * APB2CLK (MHz)                      | 84                     | 84                     | 84                     | 84
+  *----------------------------------------------------------------------------------------------------------------------------------------
+  * USB capable (48 MHz precise clock) | YES                    | YES                    | YES                    | YES
+  *----------------------------------------------------------------------------------------------------------------------------------------
   ******************************************************************************
   * @attention
   *
@@ -136,8 +136,8 @@
   */
 
 /* Select the SYSCLOCK  to start with (0=OFF, 1=ON) */
-#define USE_SYSCLOCK_168 (1) /* Use external 8MHz xtal and sets SYSCLK to 168MHz */
-#define USE_SYSCLOCK_84 (0) /* Use external 8MHz xtal and sets SYSCLK to 84MHz */
+#define USE_SYSCLOCK_168 (1) /* Use external 8MHz or 12 MHz xtal and sets SYSCLK to 168MHz */
+#define USE_SYSCLOCK_84 (0) /* Use external 8MHz or 12 MHz xtal and sets SYSCLK to 84MHz */
 
 /**
   * @}
@@ -801,7 +801,11 @@ void SetSysClock(void)
   RCC_OscInitStruct.HSEState = RCC_HSE_ON;
   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
   RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
+#ifdef USE_DEBUG_8MHz_XTAL
   RCC_OscInitStruct.PLL.PLLM = 8;
+#else
+  RCC_OscInitStruct.PLL.PLLM = 12;
+#endif
   RCC_OscInitStruct.PLL.PLLN = 336;
   RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
   RCC_OscInitStruct.PLL.PLLQ = 7;
@@ -838,7 +842,11 @@ void SetSysClock(void)
   RCC_OscInitStruct.HSEState = RCC_HSE_ON;
   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
   RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
+#ifdef USE_DEBUG_8MHz_XTAL
   RCC_OscInitStruct.PLL.PLLM = 8;
+#else
+  RCC_OscInitStruct.PLL.PLLM = 12;
+#endif
   RCC_OscInitStruct.PLL.PLLN = 336;
   RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
   RCC_OscInitStruct.PLL.PLLQ = 7;
@@ -869,4 +877,4 @@ void SetSysClock(void)
 /**
   * @}
   */    
-/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
\ No newline at end of file
diff --git a/targets/targets.json b/targets/targets.json
index e38853d7ba..292f5b60f7 100644
--- a/targets/targets.json
+++ b/targets/targets.json
@@ -1340,10 +1340,10 @@
         "default_toolchain": "ARM",
         "supported_toolchains": ["GCC_ARM", "ARM", "IAR"],
         "extra_labels": ["STM", "STM32F4", "STM32F437", "STM32F437VG", "STM32F437xx", "STM32F437xG"],
-        "macros": ["TRANSACTION_QUEUE_SIZE_SPI=2", "RTC_LSI=1"],
+        "macros": ["TRANSACTION_QUEUE_SIZE_SPI=2", "RTC_LSI=1", "HSE_VALUE=12000000"],
         "inherits": ["Target"],
-        "device_has": ["ANALOGIN", "ANALOGOUT", "I2C", "I2CSLAVE", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "SERIAL", "SLEEP", "RTC", "SPI", "SPISLAVE", "STDIO_MESSAGES", "TRNG"],
-        "features": ["LWIP"],        
+        "device_has": ["ANALOGIN", "ANALOGOUT", "I2C", "I2CSLAVE", "INTERRUPTIN", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "SERIAL", "SLEEP", "RTC", "SPI", "SPISLAVE","STDIO_MESSAGES", "TRNG"],
+        "features": ["LWIP"],
         "release_versions": ["5"],
         "device_name": "STM32F437VG"
         },