diff --git a/stddef.h b/stddef.h
index 1a5408d..24d7444 100644
--- a/stddef.h
+++ b/stddef.h
@@ -2,9 +2,9 @@
 #define _STDDEF_H
 
 #define NULL ((void *)0)
-typedef unsigned int size_t;
-typedef int wchar_t;
-typedef int ptrdiff_t;
+typedef __SIZE_TYPE__ size_t;
+typedef __WCHAR_TYPE__ wchar_t;
+typedef __PTRDIFF_TYPE__ ptrdiff_t;
 #define offsetof(type, field) ((size_t) &((type *)0)->field)
 
 /* need to do that because of glibc 2.1 bug (should have a way to test