diff --git a/configure.in b/configure.in
index c1c9dfccc..4d0901e3e 100644
--- a/configure.in
+++ b/configure.in
@@ -327,8 +327,9 @@ AC_ARG_ENABLE(scsi-directio,
   ])
 
 AC_ARG_ENABLE(parport-directio,
-  [  --enable-parport-directio  enable parallel port direct IO
-                          XXXX short description needed. [default=no]
+  [  --enable-parport-directio  enable parallel port direct IO, the backend will
+                          do direct hardware access to use parallel port, so 
+			  frontends will require special permission level. [default=no]
                           This option is in no way related to 
                           --enable-scsi-directio],
   [