diff --git a/include/psdk/ntdddisk.h b/include/psdk/ntdddisk.h
index 2aa649ccbc4..54d4229a56e 100644
--- a/include/psdk/ntdddisk.h
+++ b/include/psdk/ntdddisk.h
@@ -151,6 +151,19 @@ extern "C" {
 #define IOCTL_DISK_SET_CACHE_INFORMATION \
   CTL_CODE(IOCTL_DISK_BASE, 0x0036, METHOD_BUFFERED, FILE_READ_ACCESS | FILE_WRITE_ACCESS)
 
+//
+// NTDDI_WIN2003 was an older define used in the early beta builds, which
+// Microsoft forgot to fix in a few headers.
+// NTDDI_WS03 is the correct term.
+//
+#if (NTDDI_VERSION < NTDDI_WS03)
+#define IOCTL_DISK_GET_WRITE_CACHE_STATE \
+  CTL_CODE(IOCTL_DISK_BASE, 0x0037, METHOD_BUFFERED, FILE_READ_ACCESS)
+#else
+#define OBSOLETE_DISK_GET_WRITE_CACHE_STATE \
+  CTL_CODE(IOCTL_DISK_BASE, 0x0037, METHOD_BUFFERED, FILE_READ_ACCESS)
+#endif
+
 #define IOCTL_DISK_SET_DRIVE_LAYOUT \
   CTL_CODE(IOCTL_DISK_BASE, 0x0004, METHOD_BUFFERED, FILE_READ_ACCESS | FILE_WRITE_ACCESS)
 
@@ -183,7 +196,6 @@ extern "C" {
 #define IOCTL_DISK_GROW_PARTITION           CTL_CODE(IOCTL_DISK_BASE, 0x0034, METHOD_BUFFERED, FILE_READ_ACCESS | FILE_WRITE_ACCESS)
 #define IOCTL_DISK_GET_CACHE_INFORMATION    CTL_CODE(IOCTL_DISK_BASE, 0x0035, METHOD_BUFFERED, FILE_READ_ACCESS)
 #define IOCTL_DISK_SET_CACHE_INFORMATION    CTL_CODE(IOCTL_DISK_BASE, 0x0036, METHOD_BUFFERED, FILE_READ_ACCESS | FILE_WRITE_ACCESS)
-#define IOCTL_DISK_GET_WRITE_CACHE_STATE    CTL_CODE(IOCTL_DISK_BASE, 0x0037, METHOD_BUFFERED, FILE_READ_ACCESS)
 #define IOCTL_DISK_DELETE_DRIVE_LAYOUT      CTL_CODE(IOCTL_DISK_BASE, 0x0040, METHOD_BUFFERED, FILE_READ_ACCESS | FILE_WRITE_ACCESS)
 #define IOCTL_DISK_UPDATE_PROPERTIES        CTL_CODE(IOCTL_DISK_BASE, 0x0050, METHOD_BUFFERED, FILE_ANY_ACCESS)
 #define IOCTL_DISK_FORMAT_DRIVE             CTL_CODE(IOCTL_DISK_BASE, 0x00f3, METHOD_BUFFERED, FILE_READ_ACCESS | FILE_WRITE_ACCESS)