diff --git a/modules/locale/locale.test b/modules/locale/locale.test
index 6fcf06fe5e6..db87e05548c 100644
--- a/modules/locale/locale.test
+++ b/modules/locale/locale.test
@@ -819,7 +819,7 @@ class LocalePluralFormatTest extends DrupalWebTestCase {
    *   Additional options to pass to the translation import form.
    */
   function importPoFile($contents, array $options = array()) {
-    $name = tempnam('temporary://', "po_") . '.po';
+    $name = drupal_tempnam('temporary://', "po_") . '.po';
     file_put_contents($name, $contents);
     $options['files[file]'] = $name;
     $this->drupalPost('admin/config/regional/translate/import', $options, t('Import'));
@@ -1113,7 +1113,7 @@ class LocaleImportFunctionalTest extends DrupalWebTestCase {
    *   Additional options to pass to the translation import form.
    */
   function importPoFile($contents, array $options = array()) {
-    $name = tempnam('temporary://', "po_") . '.po';
+    $name = drupal_tempnam('temporary://', "po_") . '.po';
     file_put_contents($name, $contents);
     $options['files[file]'] = $name;
     $this->drupalPost('admin/config/regional/translate/import', $options, t('Import'));
@@ -1340,7 +1340,7 @@ class LocaleExportFunctionalTest extends DrupalWebTestCase {
   function testExportTranslation() {
     // First import some known translations.
     // This will also automatically enable the 'fr' language.
-    $name = tempnam('temporary://', "po_") . '.po';
+    $name = drupal_tempnam('temporary://', "po_") . '.po';
     file_put_contents($name, $this->getPoFile());
     $this->drupalPost('admin/config/regional/translate/import', array(
       'langcode' => 'fr',