diff --git a/src/bin/initdb/t/001_initdb.pl b/src/bin/initdb/t/001_initdb.pl
index a7bea76f52..db92a88a4e 100644
--- a/src/bin/initdb/t/001_initdb.pl
+++ b/src/bin/initdb/t/001_initdb.pl
@@ -18,27 +18,27 @@ command_fails([ 'initdb', '-S', "$tempdir/data3" ],
 mkdir "$tempdir/data4" or BAIL_OUT($!);
 command_ok([ 'initdb', "$tempdir/data4" ], 'existing empty data directory');
 
-system_or_bail "rm -rf $tempdir/*";
+system_or_bail "rm -rf '$tempdir'/*";
 
 command_ok([ 'initdb', "$tempdir/data", '-X', "$tempdir/pgxlog" ],
 	'separate xlog directory');
 
-system_or_bail "rm -rf $tempdir/*";
+system_or_bail "rm -rf '$tempdir'/*";
 command_fails(
 	[ 'initdb', "$tempdir/data", '-X', 'pgxlog' ],
 	'relative xlog directory not allowed');
 
-system_or_bail "rm -rf $tempdir/*";
+system_or_bail "rm -rf '$tempdir'/*";
 mkdir "$tempdir/pgxlog";
 command_ok([ 'initdb', "$tempdir/data", '-X', "$tempdir/pgxlog" ],
 	'existing empty xlog directory');
 
-system_or_bail "rm -rf $tempdir/*";
+system_or_bail "rm -rf '$tempdir'/*";
 mkdir "$tempdir/pgxlog";
 mkdir "$tempdir/pgxlog/lost+found";
 command_fails([ 'initdb', "$tempdir/data", '-X', "$tempdir/pgxlog" ],
 	'existing nonempty xlog directory');
 
-system_or_bail "rm -rf $tempdir/*";
+system_or_bail "rm -rf '$tempdir'/*";
 command_ok([ 'initdb', "$tempdir/data", '-T', 'german' ],
 	'select default dictionary');
diff --git a/src/bin/pg_controldata/t/001_pg_controldata.pl b/src/bin/pg_controldata/t/001_pg_controldata.pl
index 84c2fb25f3..35ad10a25c 100644
--- a/src/bin/pg_controldata/t/001_pg_controldata.pl
+++ b/src/bin/pg_controldata/t/001_pg_controldata.pl
@@ -11,6 +11,6 @@ program_options_handling_ok('pg_controldata');
 command_fails(['pg_controldata'], 'pg_controldata without arguments fails');
 command_fails([ 'pg_controldata', 'nonexistent' ],
 	'pg_controldata with nonexistent directory fails');
-system_or_bail "initdb -D $tempdir/data -A trust >/dev/null";
+system_or_bail "initdb -D '$tempdir'/data -A trust >/dev/null";
 command_like([ 'pg_controldata', "$tempdir/data" ],
 	qr/checkpoint/, 'pg_controldata produces output');
diff --git a/src/bin/pg_ctl/t/002_status.pl b/src/bin/pg_ctl/t/002_status.pl
index 28c0a2a98e..e10fd1b3e3 100644
--- a/src/bin/pg_ctl/t/002_status.pl
+++ b/src/bin/pg_ctl/t/002_status.pl
@@ -6,7 +6,7 @@ use Test::More tests => 2;
 my $tempdir = TestLib::tempdir;
 my $tempdir_short = TestLib::tempdir_short;
 
-system_or_bail "initdb -D $tempdir/data -A trust >/dev/null";
+system_or_bail "initdb -D '$tempdir'/data -A trust >/dev/null";
 open CONF, ">>$tempdir/data/postgresql.conf";
 print CONF "listen_addresses = ''\n";
 print CONF "unix_socket_directories = '$tempdir_short'\n";
diff --git a/src/test/perl/TestLib.pm b/src/test/perl/TestLib.pm
index e6a8a4ebe3..899844baf7 100644
--- a/src/test/perl/TestLib.pm
+++ b/src/test/perl/TestLib.pm
@@ -88,7 +88,7 @@ sub start_test_server
 
 	my $tempdir_short = tempdir_short;
 
-	system "initdb -D $tempdir/pgdata -A trust -N >/dev/null";
+	system "initdb -D '$tempdir'/pgdata -A trust -N >/dev/null";
 	$ret = system 'pg_ctl', '-D', "$tempdir/pgdata", '-s', '-w', '-l',
 	  "$tempdir/logfile", '-o',
 	  "--fsync=off -k $tempdir_short --listen-addresses='' --log-statement=all",
@@ -223,7 +223,7 @@ sub issues_sql_like
 		truncate $test_server_logfile, 0;
 		my $result = run $cmd, '>', \$stdout, '2>', \$stderr;
 		ok($result, "@$cmd exit code 0");
-		my $log = `cat $test_server_logfile`;
+		my $log = `cat '$test_server_logfile'`;
 		like($log, $expected_sql, "$test_name: SQL found in server log");
 	};
 }