diff --git a/bin/dd/tests/dd2_test.sh b/bin/dd/tests/dd2_test.sh
index c0b33fc1722..7632de3bde2 100755
--- a/bin/dd/tests/dd2_test.sh
+++ b/bin/dd/tests/dd2_test.sh
@@ -1,30 +1,8 @@
 #
 # Copyright (c) 2017 Spectra Logic Corporation
-# All rights reserved.
 #
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions
-# are met:
-# 1. Redistributions of source code must retain the above copyright
-#    notice, this list of conditions and the following disclaimer.
-# 2. Redistributions in binary form must reproduce the above copyright
-#    notice, this list of conditions and the following disclaimer in the
-#    documentation and/or other materials provided with the distribution.
+# SPDX-License-Identifier: BSD-2-Clause
 #
-# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
-# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
-# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
-# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-# POSSIBILITY OF SUCH DAMAGE.
-#
-# $FreeBSD$
-
 
 atf_test_case max_seek
 max_seek_head()
@@ -33,17 +11,23 @@ max_seek_head()
 }
 max_seek_body()
 {
-	case `df -T . | tail -n 1 | cut -wf 2` in
-		"ufs")
-			atf_skip "UFS's maximum file size is too small";;
-		"zfs") ;; # ZFS is fine
-		"tmpfs")
-			atf_skip "tmpfs can't create arbitrarily large spare files";;
-		*) atf_skip "Unknown file system";;
+	case $(df -T . | tail -n 1 | cut -wf 2) in
+	"ufs")
+		atf_skip "UFS's maximum file size is too small"
+		;;
+	"zfs")
+		# ZFS is fine
+		;;
+	"tmpfs")
+		atf_skip "tmpfs can't create arbitrarily large sparse files"
+		;;
+	*)
+		atf_skip "Unknown file system"
+		;;
 	esac
 
 	touch f.in
-	seek=`echo "2^63 / 4096 - 1" | bc`
+	seek=$(bc -e "2^63 / 4096 - 1")
 	atf_check -s exit:0 -e ignore dd if=f.in of=f.out bs=4096 seek=$seek
 }
 
@@ -55,7 +39,7 @@ seek_overflow_head()
 seek_overflow_body()
 {
 	touch f.in
-	seek=`echo "2^63 / 4096" | bc`
+	seek=$(bc -e "2^63 / 4096")
 	atf_check -s not-exit:0 -e match:"seek offsets cannot be larger than" \
 		dd if=f.in of=f.out bs=4096 seek=$seek
 	atf_check -s not-exit:0 -e match:"seek offsets cannot be larger than" \