diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index bcfb977..79a0b87 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -1281,7 +1281,7 @@ function drupal_find_theme_templates($cache, $extension, $path) {
   // Escape the periods in the extension.
   $regex = '/' . str_replace('.', '\.', $extension) . '$/';
   // Get a listing of all template files in the path to search.
-  $files = file_scan_directory($path, $regex, array('key' => 'name'));
+  $files = file_scan_directory($path, $regex, array('key' => 'filename'));
 
   // Find templates that implement registered theme hooks and include that in
   // what is returned so that the registry knows that the theme has this
@@ -1291,12 +1291,8 @@ function drupal_find_theme_templates($cache, $extension, $path) {
     if (strpos($file->uri, str_replace($subtheme_paths, '', $file->uri)) !== 0) {
       continue;
     }
-    // Chop off the remaining '.tpl' extension. $template already has the
-    // rightmost extension removed, but there might still be more, such as with
-    // .tpl.php, which still has .tpl in $template at this point.
-    if (($pos = strpos($template, '.tpl')) !== FALSE) {
-      $template = substr($template, 0, $pos);
-    }
+    // Remove the extension from the filename.
+    $template = str_replace($extension, '', $template);
     // Transform - in filenames to _ to match function naming scheme
     // for the purposes of searching.
     $hook = strtr($template, '-', '_');
@@ -1337,13 +1333,8 @@ function drupal_find_theme_templates($cache, $extension, $path) {
       if ($matches) {
         foreach ($matches as $match) {
           $file = $match;
-          // Chop off the remaining extensions if there are any. $template
-          // already has the rightmost extension removed, but there might still
-          // be more, such as with .tpl.php, which still has .tpl in $template
-          // at this point.
-          if (($pos = strpos($match, '.')) !== FALSE) {
-            $file = substr($match, 0, $pos);
-          }
+          // Remove the extension from the filename.
+          $file = str_replace($extension, '', $file);
           // Put the underscores back in for the hook name and register this
           // pattern.
           $arg_name = isset($info['variables']) ? 'variables' : 'render element';