diff --git a/targets/TARGET_STM/TARGET_STM32L4/TARGET_DISCO_L476VG/device/TOOLCHAIN_GCC_ARM/startup_stm32l476xx.S b/targets/TARGET_STM/TARGET_STM32L4/TARGET_DISCO_L476VG/device/TOOLCHAIN_GCC_ARM/startup_stm32l476xx.S
index fe37df3700..8e825b181c 100644
--- a/targets/TARGET_STM/TARGET_STM32L4/TARGET_DISCO_L476VG/device/TOOLCHAIN_GCC_ARM/startup_stm32l476xx.S
+++ b/targets/TARGET_STM/TARGET_STM32L4/TARGET_DISCO_L476VG/device/TOOLCHAIN_GCC_ARM/startup_stm32l476xx.S
@@ -59,10 +59,6 @@ defined in linker script */
 .word	_sdata
 /* end address for the .data section. defined in linker script */
 .word	_edata
-/* start address for the .bss section. defined in linker script */
-.word	_sbss
-/* end address for the .bss section. defined in linker script */
-.word	_ebss
 
 .equ  BootRAM,        0xF1E0F85F
 /**
@@ -96,17 +92,6 @@ LoopCopyDataInit:
 	adds	r2, r0, r1
 	cmp	r2, r3
 	bcc	CopyDataInit
-	ldr	r2, =_sbss
-	b	LoopFillZerobss
-/* Zero fill the bss segment. */
-FillZerobss:
-	movs	r3, #0
-	str	r3, [r2], #4
-
-LoopFillZerobss:
-	ldr	r3, = _ebss
-	cmp	r2, r3
-	bcc	FillZerobss
 
 /* Call the clock system intitialization function.*/
     bl  SystemInit
diff --git a/targets/TARGET_STM/TARGET_STM32L4/TARGET_L476_L486/device/TOOLCHAIN_GCC_ARM/startup_stm32l476xx.S b/targets/TARGET_STM/TARGET_STM32L4/TARGET_L476_L486/device/TOOLCHAIN_GCC_ARM/startup_stm32l476xx.S
index fe37df3700..8510b46ecd 100644
--- a/targets/TARGET_STM/TARGET_STM32L4/TARGET_L476_L486/device/TOOLCHAIN_GCC_ARM/startup_stm32l476xx.S
+++ b/targets/TARGET_STM/TARGET_STM32L4/TARGET_L476_L486/device/TOOLCHAIN_GCC_ARM/startup_stm32l476xx.S
@@ -59,11 +59,6 @@ defined in linker script */
 .word	_sdata
 /* end address for the .data section. defined in linker script */
 .word	_edata
-/* start address for the .bss section. defined in linker script */
-.word	_sbss
-/* end address for the .bss section. defined in linker script */
-.word	_ebss
-
 .equ  BootRAM,        0xF1E0F85F
 /**
  * @brief  This is the code that gets called when the processor first
@@ -96,17 +91,6 @@ LoopCopyDataInit:
 	adds	r2, r0, r1
 	cmp	r2, r3
 	bcc	CopyDataInit
-	ldr	r2, =_sbss
-	b	LoopFillZerobss
-/* Zero fill the bss segment. */
-FillZerobss:
-	movs	r3, #0
-	str	r3, [r2], #4
-
-LoopFillZerobss:
-	ldr	r3, = _ebss
-	cmp	r2, r3
-	bcc	FillZerobss
 
 /* Call the clock system intitialization function.*/
     bl  SystemInit
diff --git a/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L432KC/device/TOOLCHAIN_GCC_ARM/startup_stm32l432xx.S b/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L432KC/device/TOOLCHAIN_GCC_ARM/startup_stm32l432xx.S
index cfc614e875..c272e19398 100644
--- a/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L432KC/device/TOOLCHAIN_GCC_ARM/startup_stm32l432xx.S
+++ b/targets/TARGET_STM/TARGET_STM32L4/TARGET_NUCLEO_L432KC/device/TOOLCHAIN_GCC_ARM/startup_stm32l432xx.S
@@ -59,11 +59,6 @@ defined in linker script */
 .word	_sdata
 /* end address for the .data section. defined in linker script */
 .word	_edata
-/* start address for the .bss section. defined in linker script */
-.word	_sbss
-/* end address for the .bss section. defined in linker script */
-.word	_ebss
-
 .equ  BootRAM,        0xF1E0F85F
 /**
  * @brief  This is the code that gets called when the processor first
@@ -96,17 +91,6 @@ LoopCopyDataInit:
 	adds	r2, r0, r1
 	cmp	r2, r3
 	bcc	CopyDataInit
-	ldr	r2, =_sbss
-	b	LoopFillZerobss
-/* Zero fill the bss segment. */
-FillZerobss:
-	movs	r3, #0
-	str	r3, [r2], #4
-
-LoopFillZerobss:
-	ldr	r3, = _ebss
-	cmp	r2, r3
-	bcc	FillZerobss
 
 /* Call the clock system intitialization function.*/
     bl  SystemInit