diff --git a/cmd/zpool/zpool_main.c b/cmd/zpool/zpool_main.c
index 237e558da..2c46ad0df 100644
--- a/cmd/zpool/zpool_main.c
+++ b/cmd/zpool/zpool_main.c
@@ -456,7 +456,7 @@ get_usage(zpool_help_t idx)
 		    "<pool> <vdev> ...\n"));
 	case HELP_ATTACH:
 		return (gettext("\tattach [-fsw] [-o property=value] "
-		    "<pool> <device> <new-device>\n"));
+		    "<pool> <vdev> <new-device>\n"));
 	case HELP_CLEAR:
 		return (gettext("\tclear [[--power]|[-nF]] <pool> [device]\n"));
 	case HELP_CREATE:
@@ -7644,7 +7644,7 @@ zpool_do_replace(int argc, char **argv)
 }
 
 /*
- * zpool attach [-fsw] [-o property=value] <pool> <device>|<vdev> <new_device>
+ * zpool attach [-fsw] [-o property=value] <pool> <vdev> <new_device>
  *
  *	-f	Force attach, even if <new_device> appears to be in use.
  *	-s	Use sequential instead of healing reconstruction for resilver.
@@ -7652,9 +7652,9 @@ zpool_do_replace(int argc, char **argv)
  *	-w	Wait for resilvering (mirror) or expansion (raidz) to complete
  *		before returning.
  *
- * Attach <new_device> to a <device> or <vdev>, where the vdev can be of type
- * mirror or raidz. If <device> is not part of a mirror, then <device> will
- * be transformed into a mirror of <device> and <new_device>. When a mirror
+ * Attach <new_device> to a <vdev>, where the vdev can be of type
+ * device, mirror or raidz. If <vdev> is not part of a mirror, then <vdev> will
+ * be transformed into a mirror of <vdev> and <new_device>. When a mirror
  * is involved, <new_device> will begin life with a DTL of [0, now], and will
  * immediately begin to resilver itself. For the raidz case, a expansion will
  * commence and reflow the raidz data across all the disks including the
diff --git a/man/man8/zpool-attach.8 b/man/man8/zpool-attach.8
index f120350a5..04996ed4f 100644
--- a/man/man8/zpool-attach.8
+++ b/man/man8/zpool-attach.8
@@ -39,24 +39,24 @@
 .Cm attach
 .Op Fl fsw
 .Oo Fl o Ar property Ns = Ns Ar value Oc
-.Ar pool device new_device
+.Ar pool vdev new_device
 .
 .Sh DESCRIPTION
 Attaches
 .Ar new_device
 to the existing
-.Ar device .
+.Ar vdev .
 The behavior differs depending on if the existing
-.Ar device
+.Ar vdev
 is a RAID-Z device, or a mirror/plain device.
 .Pp
-If the existing device is a mirror or plain device
+If the existing vdev is a mirror or plain device
 .Pq e.g. specified as Qo Li sda Qc or Qq Li mirror-7 ,
-the new device will be mirrored with the existing device, a resilver will be
+the new device will be mirrored with the existing vdev, a resilver will be
 initiated, and the new device will contribute to additional redundancy once the
 resilver completes.
 If
-.Ar device
+.Ar vdev
 is not currently part of a mirrored configuration,
 .Ar device
 automatically transforms into a two-way mirror of
@@ -64,7 +64,7 @@ automatically transforms into a two-way mirror of
 and
 .Ar new_device .
 If
-.Ar device
+.Ar vdev
 is part of a two-way mirror, attaching
 .Ar new_device
 creates a three-way mirror, and so on.
@@ -72,7 +72,7 @@ In either case,
 .Ar new_device
 begins to resilver immediately and any running scrub is canceled.
 .Pp
-If the existing device is a RAID-Z device
+If the existing vdev is a RAID-Z device
 .Pq e.g. specified as Qq Ar raidz2-0 ,
 the new device will become part of that RAID-Z group.
 A "raidz expansion" will be initiated, and once the expansion completes,
@@ -112,7 +112,7 @@ the checksums of all blocks which have been copied during the expansion.
 Forces use of
 .Ar new_device ,
 even if it appears to be in use.
-Not all devices can be overridden in this manner.
+Not all vdevs can be overridden in this manner.
 .It Fl o Ar property Ns = Ns Ar value
 Sets the given pool properties.
 See the
@@ -121,7 +121,7 @@ manual page for a list of valid properties that can be set.
 The only property supported at the moment is
 .Sy ashift .
 .It Fl s
-When attaching to a mirror or plain device, the
+When attaching to a mirror or plain vdev, the
 .Ar new_device
 is reconstructed sequentially to restore redundancy as quickly as possible.
 Checksums are not verified during sequential reconstruction so a scrub is