diff --git a/winsup/cygwin/fhandler_floppy.cc b/winsup/cygwin/fhandler_floppy.cc
index 8c9ef9d02..1bb3aca6b 100644
--- a/winsup/cygwin/fhandler_floppy.cc
+++ b/winsup/cygwin/fhandler_floppy.cc
@@ -159,9 +159,9 @@ fhandler_dev_floppy::lock_partition (DWORD to_write)
   /* The simple case.  We have only a single partition open anyway.
      Try to lock the partition so that a subsequent write succeeds.
      If there's some file handle open on one of the affected partitions,
-     this fails, but that's how it works on Vista and later...
-     Only DEV_SD7_MAJOR and less can point to partition 0. */
-  if (get_major () <= DEV_SD7_MAJOR && get_minor () % 16 != 0)
+     this fails, but that's how it works...
+     The high partition major numbers don't have a partition 0. */
+  if (get_major () >= DEV_SD_HIGHPART_START || get_minor () % 16 != 0)
     {
       if (!DeviceIoControl (get_handle (), FSCTL_LOCK_VOLUME,
 			   NULL, 0, NULL, 0, &bytes_read, NULL))
@@ -297,13 +297,10 @@ fhandler_dev_floppy::write_file (const void *buf, DWORD to_write,
   *err = 0;
   if (!(ret = WriteFile (get_handle (), buf, to_write, written, 0)))
     *err = GetLastError ();
-  /* When writing to a disk or partition on Vista, an "Access denied" error
-     is potentially a result of the raw disk write restriction.  See
-     http://support.microsoft.com/kb/942448 for details.  What we have to
-     do here is to lock the partition and retry.  The previous solution
-     locked one or all partitions immediately in open.  Which is overly
-     wasteful, given that the user might only want to change, say, the boot
-     sector. */
+  /* When writing to a disk or partition an "Access denied" error may
+     occur due to the raw disk write restriction.
+     See http://support.microsoft.com/kb/942448 for details.
+     What we do here is to lock the affected partition(s) and retry. */
   if (*err == ERROR_ACCESS_DENIED
       && wincap.has_restricted_raw_disk_access ()
       && get_major () != DEV_FLOPPY_MAJOR