diff --git a/content/pages/buscar.php.md b/content/pages/buscar.php.md
index 542b02e..851cb65 100644
--- a/content/pages/buscar.php.md
+++ b/content/pages/buscar.php.md
@@ -43,7 +43,7 @@ if (isset($_GET['q'])) {
     $search_str = trim($_REQUEST['q']);
 
     $keywords = explode(' ', $search_str);
-    $keywords_temp = '';
+    $keywords_temp = NULL;
     foreach ($keywords as $keyword) {
         $is_stop_word = false;
         foreach ($STOP_WORDS as $stop_word) {
@@ -113,7 +113,7 @@ if (isset($_GET['q'])) {
             $found_results_count_str = $found_results_count . ' resultados';
         }
     } else if ($found_results_count == 0) {
-        $found_results_count_str = '';
+        $found_results_count_str = NULL;
         printf('<div id="tipue_search_warning">%s</div>', 'No se ha encontrado nada');
     }