diff --git a/configure.ac b/configure.ac
index 80fb39d..f101b86 100644
--- a/configure.ac
+++ b/configure.ac
@@ -265,6 +265,12 @@ if test "$enable_nfsv4" = yes; then
     AC_RPCSEC_VERSION
   fi
 fi
+
+if test "$enable_nfsv41" = yes; then
+  AC_CHECK_LIB([devmapper], [dm_task_create], [LIBDEVMAPPER="-ldevmapper"], AC_MSG_ERROR([libdevmapper needed]))
+  AC_CHECK_HEADER(libdevmapper.h, , AC_MSG_ERROR([Cannot find devmapper header file libdevmapper.h]))
+fi
+
 dnl enable nfsidmap when its support by libnfsidmap
 AM_CONDITIONAL(CONFIG_NFSIDMAP, [test "$ac_cv_header_keyutils_h$ac_cv_lib_nfsidmap_nfs4_owner_to_uid" = "yesyes"])
 
diff --git a/utils/blkmapd/device-process.c b/utils/blkmapd/device-process.c
index 27ff374..652a7a8 100644
--- a/utils/blkmapd/device-process.c
+++ b/utils/blkmapd/device-process.c
@@ -296,7 +296,7 @@ decode_blk_volume(uint32_t **pp, uint32_t *end, struct bl_volume *vols, int voln
 		off_t stripe_unit = vol->param.bv_stripe_unit;
 		/* Check limitations imposed by device-mapper */
 		if ((stripe_unit & (stripe_unit - 1)) != 0
-		    || stripe_unit < (off_t) (PAGE_SIZE >> 9))
+		    || stripe_unit < (off_t) (sysconf(_SC_PAGE_SIZE) >> 9))
 			return -EIO;
 		BLK_READBUF(p, end, 4);
 		READ32(vol->bv_vol_n);
diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man
index ce40933..2ad92d1 100644
--- a/utils/mount/nfs.man
+++ b/utils/mount/nfs.man
@@ -1561,10 +1561,10 @@ To ensure that the saved mount options are not erased during a remount,
 specify either the local mount directory, or the server hostname and
 export pathname, but not both, during a remount.  For example,
 .P
-.NF
-.TA 2.5i
+.nf
+.ta 8n
 	mount -o remount,ro /mnt
-.FI
+.fi
 .P
 merges the mount option
 .B ro