diff --git a/src/chinit.c b/src/chinit.c
index c7c0c7735..e57c0614e 100644
--- a/src/chinit.c
+++ b/src/chinit.c
@@ -33,7 +33,7 @@
  */
 void chSysInit(void) {
   static Thread mainthread;
-  static BYTE8 waIdleThread[UserStackSize(IDLE_THREAD_STACK_SIZE)];
+  static WorkingArea(waIdleThread, IDLE_THREAD_STACK_SIZE);
 
   chSchInit();
   chDbgInit();