diff --git a/libexec/rc/rc.d/growfs b/libexec/rc/rc.d/growfs
index 98f1d9b649c1..039813c8f3ee 100755
--- a/libexec/rc/rc.d/growfs
+++ b/libexec/rc/rc.d/growfs
@@ -57,7 +57,7 @@ growfs_start ()
 		;;
 	zfs)
 		pool=${FSDEV%%/*}
-		rootdev=$(zpool list -v $pool | tail -n 1 | awk '{ print $1 }')
+		rootdev=$(zpool list -v $pool | awk 'END { print $1 }')
 		;;
 	*)
 		echo "Don't know how to grow root filesystem type: $FSTYPE"