diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 369e868..45c7e51 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -1211,7 +1211,7 @@ function install_find_translations() {
  */
 function install_find_translation_files($langcode = NULL) {
   $directory = variable_get('locale_translate_file_directory', conf_path() . '/files/translations');
-  $files = file_scan_directory($directory, '!install\.' . (!empty($langcode) ? preg_quote($langcode, '!') : '[^\.]+') . '\.po$!', array('recurse' => FALSE));
+  $files = file_scan_directory($directory, '!drupal-\d+\.\d+\.' . (!empty($langcode) ? preg_quote($langcode, '!') : '[^\.]+') . '\.po$!', array('recurse' => FALSE));
   return $files;
 }
 
diff --git a/core/includes/install.inc b/core/includes/install.inc
index 4c9c60c..c0811d0 100644
--- a/core/includes/install.inc
+++ b/core/includes/install.inc
@@ -694,10 +694,10 @@ function st($string, array $args = array(), array $options = array()) {
   if (!isset($strings)) {
     $strings = array();
     if (isset($install_state['parameters']['langcode'])) {
-      // If the given langcode was selected, there should be at least one .po file
-      // with its name ending in install.{$install_state['parameters']['langcode']}.po
+      // If the given langcode was selected, there should be at least one .po
+      // file with its name in the pattern drupal-$version.$langcode.po.
       // This might or might not be the entire filename. It is also possible
-      // that multiple files end with the same extension, even if unlikely.
+      // that multiple files end with the same suffix, even if unlikely.
       $files = install_find_translation_files($install_state['parameters']['langcode']);
       if (!empty($files)) {
         $strings = Gettext::filesToArray($install_state['parameters']['langcode'], $files);