diff --git a/build/jam/HeadersRules b/build/jam/HeadersRules
index 741342fcc8..f0b43ed0f3 100644
--- a/build/jam/HeadersRules
+++ b/build/jam/HeadersRules
@@ -365,8 +365,11 @@ rule FStandardHeaders
 					   kernel media mail midi midi2 net opengl storage support
 					   translation ;
 
+	# GCC headers
+	local headers = $(HAIKU_GCC_HEADERS_DIR) ;
+
 	# Use headers directory, to allow to do things like include <posix/string.h>
-	local headers = [ FDirName $(HAIKU_TOP) headers ] ;
+	headers += [ FDirName $(HAIKU_TOP) headers ] ;
 
 	# Use posix headers directory
 	headers += [ FDirName $(HAIKU_TOP) headers posix ] ;
@@ -392,15 +395,6 @@ rule FStandardHeaders
 		headers += [ FDirName $(HAIKU_TOP) headers cpp ] ;
 	}
 
-	# The compiler dependent headers.
-	# TODO: Actually these directory should be listed before the posix and cpp
-	# directories, since the headers found here are supposed to override some of
-	# the headers in the latter directories. Unfortunately some of our headers
-	# are a bit messy (e.g. stddef.h) and using the compiler headers causes
-	# trouble when using different compilers (gcc 2 vs. gcc 4) and different
-	# host platforms (BeOS vs. Linux).
-	headers += $(HAIKU_GCC_HEADERS_DIR) ;
-
 	return $(headers) ;
 }
 
diff --git a/headers/posix/size_t.h b/headers/posix/size_t.h
index ad466389c1..d76a0b2d01 100644
--- a/headers/posix/size_t.h
+++ b/headers/posix/size_t.h
@@ -1,7 +1,13 @@
+/*
+ * Copyright 2008, Haiku Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ */
 #ifndef _SIZE_T_H_
 #define _SIZE_T_H_
 
-typedef unsigned long       size_t;
-typedef signed long         ssize_t;
+#include <stddef.h>
+
+// TODO: ATM gcc's stddef.h defines ssize_t for BeOS.h. We should fix this.
+//typedef long signed int		ssize_t;
 
 #endif /* _SIZE_T_H_ */
diff --git a/headers/posix/stddef.h b/headers/posix/stddef.h
deleted file mode 100644
index ce7ec9ca6e..0000000000
--- a/headers/posix/stddef.h
+++ /dev/null
@@ -1,19 +0,0 @@
-#ifndef _STDDEF_H_
-#define _STDDEF_H_
-/* 
-** Distributed under the terms of the OpenBeOS License.
-*/
-#include <null.h>
-
-#if defined(__GNUC__) && __GNUC__ > 3
-#define offsetof(type,member)   __builtin_offsetof(type, member)
-#else
-#define offsetof(type,member) ((size_t)&((type*)0)->member)
-#endif
-
-typedef long ptrdiff_t;
-
-#include <wchar_t.h>
-#include <size_t.h>
-
-#endif	/* _STDDEF_H_ */
diff --git a/headers/posix/wchar.h b/headers/posix/wchar.h
index 404dc19f4e..6aa23938f8 100644
--- a/headers/posix/wchar.h
+++ b/headers/posix/wchar.h
@@ -7,11 +7,22 @@
 #ifndef _WCHAR_H
 #define _WCHAR_H
 
-#include <wchar_t.h>
+#include <stddef.h>
 #include <stdio.h>
 
+// stddef.h is not supposed to define wint_t, but gcc 2.95.3's one does.
+// In all other cases we will do that.
+#ifndef _WINT_T
 #define _WINT_T
-typedef unsigned int wint_t;
+
+#ifndef __WINT_TYPE__
+#define __WINT_TYPE__ unsigned int
+#endif
+
+typedef __WINT_TYPE__ wint_t;
+
+#endif	// _WINT_T
+
 typedef int wctype_t;
 
 typedef struct {
@@ -19,7 +30,6 @@ typedef struct {
 	wint_t	__value;
 } mbstate_t;
 
-#include <size_t.h>
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/headers/posix/wchar_t.h b/headers/posix/wchar_t.h
index 5db297e8f1..9572a62dc1 100644
--- a/headers/posix/wchar_t.h
+++ b/headers/posix/wchar_t.h
@@ -1,15 +1,7 @@
 /*
- * Copyright (C) 2002 Marcus Overhagen
- * All rights reserved.
- *
- * Distributed under the terms of the MIT license
+ * Copyright 2008, Haiku Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
  */
-#ifndef _WCHAR_T_H
-#define _WCHAR_T_H
-
-#if !defined(__cplusplus) || __GNUC__ < 3
-typedef unsigned short wchar_t;
-#endif
-
-#endif	/* _WCHAR_T_H */
 
+// Include GCC's stddef.h. It defines wchar_t.
+#include <stddef.h>