diff --git a/src/test/ssl/t/001_ssltests.pl b/src/test/ssl/t/001_ssltests.pl
index 37ea9ee687..4eb181bd04 100644
--- a/src/test/ssl/t/001_ssltests.pl
+++ b/src/test/ssl/t/001_ssltests.pl
@@ -42,6 +42,7 @@ my $common_connstr;
 # This changes to using keys stored in a temporary path for the rest of
 # the tests. To get the full path for inclusion in connection strings, the
 # %key hash can be interrogated.
+my $cert_tempdir = PostgreSQL::Test::Utils::tempdir();
 my %key;
 my @keys = (
 	"client.key",               "client-revoked.key",
@@ -49,21 +50,23 @@ my @keys = (
 	"client-encrypted-der.key", "client-dn.key");
 foreach my $keyfile (@keys)
 {
-	copy("ssl/${keyfile}", "${PostgreSQL::Test::Utils::tmp_check}/${keyfile}")
+	copy("ssl/$keyfile", "$cert_tempdir/$keyfile")
 	  or die
-	  "couldn't copy ssl/${keyfile} to ${PostgreSQL::Test::Utils::tmp_check}/${keyfile} for permissions change: $!";
-	chmod 0600, "${PostgreSQL::Test::Utils::tmp_check}/${keyfile}"
-	  or die "failed to change permissions on ${PostgreSQL::Test::Utils::tmp_check}/${keyfile}: $!";
-
-	$key{$keyfile} = "${PostgreSQL::Test::Utils::tmp_check}/$keyfile";
+	  "couldn't copy ssl/$keyfile to $cert_tempdir/$keyfile for permissions change: $!";
+	chmod 0600, "$cert_tempdir/$keyfile"
+	  or die "failed to change permissions on $cert_tempdir/$keyfile: $!";
+	$key{$keyfile} = PostgreSQL::Test::Utils::perl2host("$cert_tempdir/$keyfile");
 }
 
 # Also make a copy of that explicitly world-readable.  We can't
 # necessarily rely on the file in the source tree having those
 # permissions.
-copy("ssl/client.key", "${PostgreSQL::Test::Utils::tmp_check}/client_wrongperms.key");
-chmod 0644, "${PostgreSQL::Test::Utils::tmp_check}/client_wrongperms.key";
-$key{'client_wrongperms.key'} = "${PostgreSQL::Test::Utils::tmp_check}/client_wrongperms.key";
+copy("ssl/client.key", "$cert_tempdir/client_wrongperms.key")
+  or die
+  "couldn't copy ssl/client_key to $cert_tempdir/client_wrongperms.key for permission change: $!";
+chmod 0644, "$cert_tempdir/client_wrongperms.key"
+  or die "failed to change permissions on $cert_tempdir/client_wrongperms.key: $!";
+$key{'client_wrongperms.key'} = PostgreSQL::Test::Utils::perl2host("$cert_tempdir/client_wrongperms.key");
 
 #### Set up the server.
 
diff --git a/src/test/ssl/t/002_scram.pl b/src/test/ssl/t/002_scram.pl
index e8831e5ee8..b965ff038a 100644
--- a/src/test/ssl/t/002_scram.pl
+++ b/src/test/ssl/t/002_scram.pl
@@ -95,9 +95,13 @@ $node->connect_fails(
 # because channel binding is not performed.  Note that ssl/client.key may
 # be used in a different test, so the name of this temporary client key
 # is chosen here to be unique.
-my $client_tmp_key = "${PostgreSQL::Test::Utils::tmp_check}/client_scram.key";
-copy("ssl/client.key", $client_tmp_key);
-chmod 0600, $client_tmp_key;
+my $cert_tempdir = PostgreSQL::Test::Utils::tempdir();
+my $client_tmp_key = PostgreSQL::Test::Utils::perl2host("$cert_tempdir/client_scram.key");
+copy("ssl/client.key", "$cert_tempdir/client_scram.key")
+  or die
+  "couldn't copy ssl/client_key to $cert_tempdir/client_scram.key for permission change: $!";
+chmod 0600, "$cert_tempdir/client_scram.key"
+  or die "failed to change permissions on $cert_tempdir/client_scram.key: $!";
 $node->connect_fails(
 	"sslcert=ssl/client.crt sslkey=$client_tmp_key sslrootcert=invalid hostaddr=$SERVERHOSTADDR dbname=certdb user=ssltestuser channel_binding=require",
 	"Cert authentication and channel_binding=require",
diff --git a/src/test/ssl/t/003_sslinfo.pl b/src/test/ssl/t/003_sslinfo.pl
index cf2e8dde0f..448742129f 100644
--- a/src/test/ssl/t/003_sslinfo.pl
+++ b/src/test/ssl/t/003_sslinfo.pl
@@ -37,11 +37,13 @@ my $common_connstr;
 
 # The client's private key must not be world-readable, so take a copy
 # of the key stored in the code tree and update its permissions.
-my $client_tmp_key = "${PostgreSQL::Test::Utils::tmp_check}/client_ext.key";
-copy("ssl/client_ext.key", $client_tmp_key)
-  or die "couldn't copy ssl/client_ext.key to $client_tmp_key for permissions change: $!";
-chmod 0600, $client_tmp_key
-  or die "failed to change permissions on $client_tmp_key: $!";
+my $cert_tempdir = PostgreSQL::Test::Utils::tempdir();
+my $client_tmp_key = PostgreSQL::Test::Utils::perl2host("$cert_tempdir/client_ext.key");
+copy("ssl/client_ext.key", "$cert_tempdir/client_ext.key")
+  or die
+  "couldn't copy ssl/client_ext.key to $cert_tempdir/client_ext.key for permissions change: $!";
+chmod 0600, "$cert_tempdir/client_ext.key"
+  or die "failed to change permissions on $cert_tempdir/client_ext.key: $!";
 
 #### Set up the server.