diff --git a/core/modules/dblog/src/Form/DblogFilterForm.php b/core/modules/dblog/src/Form/DblogFilterForm.php
index 64d0fbf..cbf8dd0 100644
--- a/core/modules/dblog/src/Form/DblogFilterForm.php
+++ b/core/modules/dblog/src/Form/DblogFilterForm.php
@@ -22,7 +22,7 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, FormStateInterface $form_state) {
-    $filters = $this->logFilters();
+    $filters = static::logFilters();
 
     $form['filters'] = array(
       '#type' => 'details',
@@ -74,7 +74,7 @@ public function validateForm(array &$form, FormStateInterface $form_state) {
    * {@inheritdoc}
    */
   public function submitForm(array &$form, FormStateInterface $form_state) {
-    $filters = $this->logFilters();
+    $filters = static::logFilters();
     foreach ($filters as $name => $filter) {
       if ($form_state->hasValue($name)) {
         $_SESSION['dblog_overview_filter'][$name] = $form_state->getValue($name);
@@ -109,7 +109,7 @@ public static function logFilters() {
     $filters = array();
 
     foreach (_dblog_get_message_types() as $type) {
-      $types[$type] = $this->t($type);
+      $types[$type] = t($type);
     }
 
     if (!empty($types)) {
@@ -130,3 +130,4 @@ public static function logFilters() {
   }
 
 }
+