diff --git a/mingw-w64-headers/crt/ChangeLog b/mingw-w64-headers/crt/ChangeLog
index 42aae4f..1729ade 100644
--- a/mingw-w64-headers/crt/ChangeLog
+++ b/mingw-w64-headers/crt/ChangeLog
@@ -1,3 +1,7 @@
+2011-01-23  Ozkan Sezer  <sezeroz@gmail.com>
+
+	* dos.h (_A_VOLID): Add missing definition, from r/os svn r50165.
+
 2011-01-02  Kai Tietz  <kai.tietz@onevision.com>
 
 	* sec_api/string_s.h: Add missing API prototypes.
diff --git a/mingw-w64-headers/crt/dos.h b/mingw-w64-headers/crt/dos.h
index dcc4483..2983aab 100644
--- a/mingw-w64-headers/crt/dos.h
+++ b/mingw-w64-headers/crt/dos.h
@@ -30,8 +30,9 @@
 #define _A_RDONLY 0x01
 #define _A_HIDDEN 0x02
 #define _A_SYSTEM 0x04
+#define _A_VOLID  0x08
 #define _A_SUBDIR 0x10
-#define _A_ARCH 0x20
+#define _A_ARCH   0x20
 
 #ifndef _GETDISKFREE_DEFINED
 #define _GETDISKFREE_DEFINED