--- dosfstools-2.10/mkdosfs/mkdosfs.c.argfix	2003-06-14 22:07:08.000000000 +0200
+++ dosfstools-2.10/mkdosfs/mkdosfs.c	2004-12-07 15:38:38.798018438 +0100
@@ -1619,6 +1619,12 @@
   if (optind < argc)
     {
       device_name = argv[optind];  /* Determine the number of blocks in the FS */
+
+      if (!device_name) {
+	  printf("No device specified.\n");
+	  usage();
+      }
+
       if (!create)
          i = count_blocks (device_name); /*  Have a look and see! */
     }