diff --git a/hal/targets/cmsis/TARGET_Freescale/TARGET_KLXX/TARGET_KL46Z/TOOLCHAIN_IAR/MKL46Z4.icf b/hal/targets/cmsis/TARGET_Freescale/TARGET_KLXX/TARGET_KL46Z/TOOLCHAIN_IAR/MKL46Z4.icf
index 673f212eba..2a765b6731 100644
--- a/hal/targets/cmsis/TARGET_Freescale/TARGET_KLXX/TARGET_KL46Z/TOOLCHAIN_IAR/MKL46Z4.icf
+++ b/hal/targets/cmsis/TARGET_Freescale/TARGET_KLXX/TARGET_KL46Z/TOOLCHAIN_IAR/MKL46Z4.icf
@@ -13,7 +13,7 @@ define symbol __ICFEDIT_region_RAM_end__   = 0x1fffffff;
 /*-Sizes-*/
 /*Heap 1/4 of ram and stack 1/8*/
 define symbol __ICFEDIT_size_cstack__ = 0x1000;
-define symbol __ICFEDIT_size_heap__   = 0x2000;
+define symbol __ICFEDIT_size_heap__   = 0x4000;
 /**** End of ICF editor section. ###ICF###*/
 
 define symbol __region_RAM2_start__ 		= 0x20000000;