diff --git a/ext/standard/tests/mail/gh19188_mixed_mode.phpt b/ext/standard/tests/mail/gh19188_mixed_mode.phpt
index fa5eb63bd4fe..5370da6fe892 100644
--- a/ext/standard/tests/mail/gh19188_mixed_mode.phpt
+++ b/ext/standard/tests/mail/gh19188_mixed_mode.phpt
@@ -1,18 +1,20 @@
 --TEST--
 GH-19188: mail.cr_lf_mode=mixed
+--ENV--
+TEST_NAME={TEST_NAME}
 --INI--
-sendmail_path={MAIL:gh19188_mixed_mode.out}
+sendmail_path={MAIL:{TEST_NAME}.out}
 mail.cr_lf_mode=mixed
 --FILE--
 <?php
 var_dump(mail('user@example.com', 'Test Subject', 'A Message', 'X-Test: mixed'));
-$mail = file_get_contents('gh19188_mixed_mode.out');
+$mail = file_get_contents(getenv('TEST_NAME') . '.out');
 echo "Mixed mode:\n";
 var_dump(preg_match_all('/(?<!\r)\n/', $mail));
 ?>
 --CLEAN--
 <?php
-@unlink('gh19188_mixed_mode.out');
+@unlink(getenv('TEST_NAME') . '.out');
 ?>
 --EXPECT--
 bool(true)
diff --git a/run-tests.php b/run-tests.php
index 8728c0d7524b..1f4299dfc123 100755
--- a/run-tests.php
+++ b/run-tests.php
@@ -2137,23 +2137,23 @@ function run_test(string $php, $file, array $env): string
         $temp_dir = str_replace($temp_source, $temp_target, $temp_dir);
     }
 
-    $main_file_name = basename($file, 'phpt');
-
-    $diff_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'diff';
-    $log_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'log';
-    $exp_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'exp';
-    $stdin_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'stdin';
-    $output_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'out';
-    $memcheck_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'mem';
-    $sh_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'sh';
-    $temp_file = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'php';
-    $test_file = $test_dir . DIRECTORY_SEPARATOR . $main_file_name . 'php';
-    $temp_skipif = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'skip.php';
-    $test_skipif = $test_dir . DIRECTORY_SEPARATOR . $main_file_name . 'skip.php';
-    $temp_clean = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'clean.php';
-    $test_clean = $test_dir . DIRECTORY_SEPARATOR . $main_file_name . 'clean.php';
-    $preload_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'preload.php';
-    $tmp_post = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . 'post';
+    $main_file_name = basename($file, '.phpt');
+
+    $diff_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.diff';
+    $log_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.log';
+    $exp_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.exp';
+    $stdin_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.stdin';
+    $output_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.out';
+    $memcheck_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.mem';
+    $sh_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.sh';
+    $temp_file = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.php';
+    $test_file = $test_dir . DIRECTORY_SEPARATOR . $main_file_name . '.php';
+    $temp_skipif = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.skip.php';
+    $test_skipif = $test_dir . DIRECTORY_SEPARATOR . $main_file_name . '.skip.php';
+    $temp_clean = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.clean.php';
+    $test_clean = $test_dir . DIRECTORY_SEPARATOR . $main_file_name . '.clean.php';
+    $preload_filename = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.preload.php';
+    $tmp_post = $temp_dir . DIRECTORY_SEPARATOR . $main_file_name . '.post';
     $tmp_relative_file = str_replace(__DIR__ . DIRECTORY_SEPARATOR, '', $test_file) . 't';
 
     if ($temp_source && $temp_target) {
@@ -2206,6 +2206,7 @@ function run_test(string $php, $file, array $env): string
 
     if ($test->sectionNotEmpty('ENV')) {
         $env_str = str_replace('{PWD}', dirname($file), $test->getSection('ENV'));
+        $env_str = str_replace('{TEST_NAME}', $main_file_name, $env_str);
         foreach (explode("\n", $env_str) as $e) {
             $e = explode('=', trim($e), 2);
 
@@ -2289,6 +2290,7 @@ function run_test(string $php, $file, array $env): string
     // these may overwrite the test defaults...
     if ($test->hasSection('INI')) {
         $ini = str_replace('{PWD}', dirname($file), $test->getSection('INI'));
+        $ini = str_replace('{TEST_NAME}', $main_file_name, $ini);
         $ini = str_replace('{TMP}', sys_get_temp_dir(), $ini);
         $replacement = IS_WINDOWS ? '"' . PHP_BINARY . ' -r \"while ($in = fgets(STDIN)) echo $in;\" > $1"' : 'tee $1 >/dev/null';
         $ini = preg_replace('/{MAIL:(\S+)}/', $replacement, $ini);
diff --git a/tests/run-test/testname_environment.phpt b/tests/run-test/testname_environment.phpt
new file mode 100644
index 000000000000..1318b811d049
--- /dev/null
+++ b/tests/run-test/testname_environment.phpt
@@ -0,0 +1,11 @@
+--TEST--
+TEST_NAME placeholder in --ENV--
+--ENV--
+TEST_PWD={PWD}
+TEST_NAME={TEST_NAME}
+--FILE--
+<?php
+echo str_replace('\\', '/', getenv('TEST_PWD') . '/' . getenv('TEST_NAME')), PHP_EOL;
+?>
+--EXPECTF--
+%stests/run-test/testname_environment