diff --git a/review/simpletest/pifr_simpletest.client.inc b/review/simpletest/pifr_simpletest.client.inc
index 39f7166..8a7a88b 100644
--- a/review/simpletest/pifr_simpletest.client.inc
+++ b/review/simpletest/pifr_simpletest.client.inc
@@ -204,16 +204,23 @@ class pifr_client_review_pifr_simpletest extends pifr_client_review_pifr_drupal
           $args[] = str_replace($this->checkout_directory . '/', '', $file->filename);
         }
       }
+      if (count($args) < 1) {
+        $this->set_error(array('@reason' => 'No valid tests specified.  (Empty run-tests.sh --file argument.)'));
+      }
       return '--file ' . implode(',', $args);
     }
     elseif (!empty($this->arguments['test.directory.review'][0])) {
-      // Remove any none test files.
-      $files = $this->syntax_files();
-      foreach ($files as $key => $file) {
-        if (pathinfo($file, PATHINFO_EXTENSION) != 'test') {
-          unset($files[$key]);
+      $files = array();
+      // Scan the 'test.directory.review' directory for '.test' files
+      foreach ($this->arguments['test.directory.review'] as $directory) {
+        $scan = file_scan_directory($this->checkout_directory . '/' . $directory, '\.test$');
+        foreach ($scan as $file) {
+          $files[] = str_replace($this->checkout_directory . '/', '', $file->filename);
         }
       }
+      if (count($files) < 1) {
+        $this->set_error(array('@reason' => 'No valid tests specified.  (Empty run-tests.sh --file argument.)'));
+      }
       return '--file ' . implode(',', $files);
     }
     elseif (PIFR_SHORTCUT_CORE_TEST) {