diff --git a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/TARGET_MTB_STM32_F439/system_clock.c b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/TARGET_MTB_STM32_F439/system_clock.c
index 24cb974c95..c0b8d42444 100644
--- a/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/TARGET_MTB_STM32_F439/system_clock.c
+++ b/targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/TARGET_MTB_STM32_F439/system_clock.c
@@ -178,8 +178,6 @@ uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
         return 0; // FAIL
     }
 
-    // HAL_RCC_MCOConfig(RCC_MCO2, RCC_MCO2SOURCE_SYSCLK, RCC_MCODIV_3);
-
     return 1;
 }
 #endif /* ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) */
@@ -233,8 +231,6 @@ uint8_t SetSysClock_PLL_HSI(void)
         return 0; // FAIL
     }
 
-    // HAL_RCC_MCOConfig(RCC_MCO2, RCC_MCO2SOURCE_SYSCLK, RCC_MCODIV_3);
-
     return 1;
 }
 #endif /* ((CLOCK_SOURCE) & USE_PLL_HSI) */