diff --git a/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/device/TOOLCHAIN_IAR/stm32f070xb.icf b/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/device/TOOLCHAIN_IAR/stm32f070xb.icf
index b7bf91b562..1833a0c2a1 100644
--- a/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/device/TOOLCHAIN_IAR/stm32f070xb.icf
+++ b/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F070RB/device/TOOLCHAIN_IAR/stm32f070xb.icf
@@ -9,7 +9,7 @@ define symbol __ICFEDIT_region_ROM_end__   = 0x0801FFFF;
 define symbol __ICFEDIT_region_RAM_start__ = 0x200000C0;
 define symbol __ICFEDIT_region_RAM_end__   = 0x20003FFF;
 /*-Sizes-*/
-define symbol __ICFEDIT_size_cstack__ = 0x800;
+define symbol __ICFEDIT_size_cstack__ = 0x400;
 define symbol __ICFEDIT_size_heap__   = 0x1000;
 /**** End of ICF editor section. ###ICF###*/
 
diff --git a/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/device/TOOLCHAIN_IAR/stm32f072xb.icf b/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/device/TOOLCHAIN_IAR/stm32f072xb.icf
index 44b77e7ac3..61a5f17c48 100644
--- a/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/device/TOOLCHAIN_IAR/stm32f072xb.icf
+++ b/targets/TARGET_STM/TARGET_STM32F0/TARGET_NUCLEO_F072RB/device/TOOLCHAIN_IAR/stm32f072xb.icf
@@ -9,7 +9,7 @@ define symbol __ICFEDIT_region_ROM_end__   = 0x0801FFFF;
 define symbol __ICFEDIT_region_RAM_start__ = 0x200000C0;
 define symbol __ICFEDIT_region_RAM_end__   = 0x20003FFF;
 /*-Sizes-*/
-define symbol __ICFEDIT_size_cstack__ = 0x800;
+define symbol __ICFEDIT_size_cstack__ = 0x400;
 define symbol __ICFEDIT_size_heap__   = 0x1000;
 /**** End of ICF editor section. ###ICF###*/