diff --git a/devices/MKL03Z4/gcc/MKL03Z32xxx4_flash.ld b/devices/MKL03Z4/gcc/MKL03Z32xxx4_flash.ld
index 72c5fc0..a2221c0 100644
--- a/devices/MKL03Z4/gcc/MKL03Z32xxx4_flash.ld
+++ b/devices/MKL03Z4/gcc/MKL03Z32xxx4_flash.ld
@@ -238,6 +238,7 @@ SECTIONS
     . = ALIGN(8);
     __end__ = .;
     PROVIDE(end = .);
+    _pvHeapStart = .; /* Add for _sbrk */
     __HeapBase = .;
     . += HEAP_SIZE;
     __HeapLimit = .;