diff --git a/targets/TARGET_Samsung/TARGET_SIDK_S5JS100/device/TOOLCHAIN_IAR/sidk_s5js100.icf b/targets/TARGET_Samsung/TARGET_SIDK_S5JS100/device/TOOLCHAIN_IAR/sidk_s5js100.icf
index c6ed833715..9e40c66181 100755
--- a/targets/TARGET_Samsung/TARGET_SIDK_S5JS100/device/TOOLCHAIN_IAR/sidk_s5js100.icf
+++ b/targets/TARGET_Samsung/TARGET_SIDK_S5JS100/device/TOOLCHAIN_IAR/sidk_s5js100.icf
@@ -42,7 +42,7 @@ define region ROM_REGION    = mem:[from S5JS100_CODE_BASE to S5JS100_CODE_END];
 define region IRAM_REGION   = mem:[from S5JS100_IRAM_BASE to S5JS100_IRAM_END];
 
 define block CSTACK with alignment = 8, size = CSTACK_SIZE { };
-define block HEAP   with alignment = 8, size = __ICFEDIT_size_heap__ { };
+define block HEAP   with expanding size, alignment = 8, minimum size = __ICFEDIT_size_heap__ { };
 define block RW     { readwrite };
 define block ZI     { zi };