diff --git a/targets/TARGET_STM/TARGET_STM32F2/TARGET_NUCLEO_F207ZG/device/TOOLCHAIN_IAR/stm32f207xx.icf b/targets/TARGET_STM/TARGET_STM32F2/TARGET_NUCLEO_F207ZG/device/TOOLCHAIN_IAR/stm32f207xx.icf
index 7432e2bcf19..b82a5368cba 100644
--- a/targets/TARGET_STM/TARGET_STM32F2/TARGET_NUCLEO_F207ZG/device/TOOLCHAIN_IAR/stm32f207xx.icf
+++ b/targets/TARGET_STM/TARGET_STM32F2/TARGET_NUCLEO_F207ZG/device/TOOLCHAIN_IAR/stm32f207xx.icf
@@ -21,7 +21,7 @@ define region RAM_region = mem:[from __region_RAM_start__ to __region_RAM_end__]
 /* Stack: 1024B */
 /* Heap: 64kB */
 define symbol __size_cstack__ = 0x400;
-define symbol __size_heap__   = 0x10000;
+define symbol __size_heap__   = 0xF000;
 define block CSTACK    with alignment = 8, size = __size_cstack__   { };
 define block HEAP      with alignment = 8, size = __size_heap__     { };
 define block STACKHEAP with fixed order { block HEAP, block CSTACK };