diff --git a/src/bin/pg_verifybackup/t/003_corruption.pl b/src/bin/pg_verifybackup/t/003_corruption.pl
index 882d75d9dc2..405ea793b68 100644
--- a/src/bin/pg_verifybackup/t/003_corruption.pl
+++ b/src/bin/pg_verifybackup/t/003_corruption.pl
@@ -13,6 +13,7 @@ use PostgreSQL::Test::Utils;
 use Test::More;
 
 my $tar = $ENV{TAR};
+my @tar_p_flags = tar_portability_options($tar);
 
 my $primary = PostgreSQL::Test::Cluster->new('primary');
 $primary->init(allows_streaming => 1);
@@ -154,8 +155,8 @@ for my $scenario (@scenario)
 		# have a TAR program available. Note that this destructively modifies
 		# the backup directory.
 		if (   !$scenario->{'needs_unix_permissions'}
-			|| !defined $tar
-			|| $tar eq '')
+			&& defined $tar
+			&& $tar ne '')
 		{
 			my $tar_backup_path = $primary->backup_dir . '/tar_' . $name;
 			mkdir($tar_backup_path) || die "mkdir $tar_backup_path: $!";
@@ -171,14 +172,23 @@ for my $scenario (@scenario)
 
 				chdir($tspath) || die "chdir: $!";
 				command_ok(
-					[ $tar, '-cf', "$tar_backup_path/$tsoid.tar", '.' ]);
+					[
+						$tar, @tar_p_flags,
+						'-cf' => "$tar_backup_path/$tsoid.tar",
+						'.'
+					]);
 				chdir($cwd) || die "chdir: $!";
 				rmtree($tspath);
 			}
 
 			# tar and remove pg_wal
 			chdir($backup_path . '/pg_wal') || die "chdir: $!";
-			command_ok([ $tar, '-cf', "$tar_backup_path/pg_wal.tar", '.' ]);
+			command_ok(
+				[
+					$tar, @tar_p_flags,
+					'-cf' => "$tar_backup_path/pg_wal.tar",
+					'.'
+				]);
 			chdir($cwd) || die "chdir: $!";
 			rmtree($backup_path . '/pg_wal');
 
@@ -190,7 +200,12 @@ for my $scenario (@scenario)
 
 			# Construct base.tar with what's left.
 			chdir($backup_path) || die "chdir: $!";
-			command_ok([ $tar, '-cf' => "$tar_backup_path/base.tar", '.' ]);
+			command_ok(
+				[
+					$tar, @tar_p_flags,
+					'-cf' => "$tar_backup_path/base.tar",
+					'.'
+				]);
 			chdir($cwd) || die "chdir: $!";
 
 			command_fails_like(
diff --git a/src/bin/pg_waldump/t/001_basic.pl b/src/bin/pg_waldump/t/001_basic.pl
index ce1f6aa30c0..a268f0f1dd0 100644
--- a/src/bin/pg_waldump/t/001_basic.pl
+++ b/src/bin/pg_waldump/t/001_basic.pl
@@ -11,15 +11,7 @@ use Test::More;
 use List::Util qw(shuffle);
 
 my $tar = $ENV{TAR};
-my @tar_c_flags;
-
-# By default, bsdtar archives sparse files in GNU tar's --format=posix --sparse
-# format, so pg_waldump can't find files that ZFS has decided to store with
-# holes.  Turn that off.
-if (system("$tar --no-read-sparse -c - /dev/null > /dev/null") == 0)
-{
-  push(@tar_c_flags, "--no-read-sparse");
-}
+my @tar_p_flags = tar_portability_options($tar);
 
 program_help_ok('pg_waldump');
 program_version_ok('pg_waldump');
@@ -355,7 +347,7 @@ sub generate_archive
 	# move into the WAL directory before archiving files
 	my $cwd = getcwd;
 	chdir($directory) || die "chdir: $!";
-	command_ok([$tar, @tar_c_flags, $compression_flags, $archive, @files]);
+	command_ok([ $tar, @tar_p_flags, $compression_flags, $archive, @files ]);
 	chdir($cwd) || die "chdir: $!";
 }
 
@@ -389,7 +381,7 @@ for my $scenario (@scenarios)
 	SKIP:
 	{
 		skip "tar command is not available", 56
-		  if !defined $tar && $scenario->{'is_archive'};
+		  if (!defined $tar || $tar eq '') && $scenario->{'is_archive'};
 		skip "$scenario->{'compression_method'} compression not supported by this build", 56
 		  if !$scenario->{'enabled'} && $scenario->{'is_archive'};
 
diff --git a/src/test/perl/PostgreSQL/Test/Utils.pm b/src/test/perl/PostgreSQL/Test/Utils.pm
index 163d9a4beb9..120999f6ac9 100644
--- a/src/test/perl/PostgreSQL/Test/Utils.pm
+++ b/src/test/perl/PostgreSQL/Test/Utils.pm
@@ -99,6 +99,8 @@ our @EXPORT = qw(
   command_ok_or_fails_like
   command_checks_all
 
+  tar_portability_options
+
   $windows_os
   $is_msys2
   $use_unix_sockets
@@ -1304,6 +1306,48 @@ sub command_checks_all
 
 =pod
 
+=item tar_portability_options(tar)
+
+Check for non-default options we need to give to tar to create
+a tarfile we can decode (i.e., no "pax" extensions).
+Not needed in tests that only use tar to read tarfiles.
+
+Returns options as an array.
+
+=cut
+
+sub tar_portability_options
+{
+	local $Test::Builder::Level = $Test::Builder::Level + 1;
+
+	my ($tar) = @_;
+
+	my @tar_p_flags = ();
+
+	return @tar_p_flags if (!defined $tar || $tar eq '');
+
+	# GNU tar typically produces gnu-format archives, which we can read fine.
+	# But some platforms configure it to default to posix/pax format, and
+	# apparently they enable --sparse too.  Override that.
+	if (system("$tar --format=ustar -c -O /dev/null >/dev/null 2>/dev/null")
+		== 0)
+	{
+		push(@tar_p_flags, "--format=ustar");
+	}
+
+	# bsdtar also archives sparse files by default, but it spells the switch
+	# to disable that differently.
+	if (system("$tar --no-read-sparse -c - /dev/null >/dev/null 2>/dev/null")
+		== 0)
+	{
+		push(@tar_p_flags, "--no-read-sparse");
+	}
+
+	return @tar_p_flags;
+}
+
+=pod
+
 =back
 
 =cut