diff --git a/import/taxonomy_csv.import.api.inc b/import/taxonomy_csv.import.api.inc
index 0ab4752..3bb651a 100644
--- a/import/taxonomy_csv.import.api.inc
+++ b/import/taxonomy_csv.import.api.inc
@@ -520,8 +520,12 @@ function _taxonomy_csv_vocabulary_import_finished($success, $results, $operation
       WATCHDOG_WARNING => t('Warnings have been reported during import process (bad formatted lines). !total_lines lines processed. First line skipped is line !line [!worst_msg].', $variables),
       WATCHDOG_ERROR   => t('Errors have been reported during import process. Process failed at line !line of a total of !total_lines [!worst_msg].', $variables),
     );
+    // Set default message
+    $message = $messages[WATCHDOG_DEBUG];
     $worst_level = intval($options['worst_message'] / 100);
-    $message = $messages[$worst_level];
+    if (isset($messages[$worst_level])) {
+      $message = $messages[$worst_level];
+    }
   }
   else {
     $message = t('Importation failed. Import process was successful until the line !line_count of a total of !total_lines. You can first check your file on this line and check file uploading.', array(