Index: boot/generic/src/str.c
===================================================================
--- boot/generic/src/str.c	(revision d735e2e934b8d024cd14b4f088821f9d2649e913)
+++ boot/generic/src/str.c	(revision 35ebd42e880816820d1be5053efa0e05335b294e)
@@ -104,5 +104,5 @@
 
 /** Check the condition if wchar_t is signed */
-#ifdef WCHAR_IS_UNSIGNED
+#ifdef __WCHAR_UNSIGNED__
 	#define WCHAR_SIGNED_CHECK(cond)  (true)
 #else