diff --git a/core/lib/Drupal/Core/Config/ConfigFactoryOverrideBase.php b/core/lib/Drupal/Core/Config/ConfigFactoryOverrideBase.php
index d443c05..18d2ee8 100644
--- a/core/lib/Drupal/Core/Config/ConfigFactoryOverrideBase.php
+++ b/core/lib/Drupal/Core/Config/ConfigFactoryOverrideBase.php
@@ -65,9 +65,9 @@ static function getSubscribedEvents() {
    * @param \Drupal\Core\Config\StorableConfigBase $override
    *   Override object corresponding to the configuration to filter data in.
    */
-  static function filterOverride(Config $config, StorableConfigBase $override) {
+  protected function filterOverride(Config $config, StorableConfigBase $override) {
     $override_data = $override->get();
-    static::filterNestedArray($config->get(), $override_data);
+    $this->filterNestedArray($config->get(), $override_data);
     if (empty($override_data)) {
       // If no override values are left that would apply, remove the override.
       $override->delete();
@@ -86,7 +86,7 @@ static function filterOverride(Config $config, StorableConfigBase $override) {
    * @param array $override_data
    *   Override data to filter.
    */
-  static function filterNestedArray(array $original_data, array &$override_data) {
+  protected function filterNestedArray(array $original_data, array &$override_data) {
     foreach ($override_data as $key => $value) {
       if (!isset($original_data[$key])) {
         // The original data is not there anymore, remove the override.
@@ -95,7 +95,7 @@ static function filterNestedArray(array $original_data, array &$override_data) {
       elseif (is_array($override_data[$key])) {
         if (is_array($original_data[$key])) {
           // Do the filtering one level deeper.
-          static::filterNestedArray($original_data[$key], $override_data[$key]);
+          $this->filterNestedArray($original_data[$key], $override_data[$key]);
           // If no overrides are left under this level, remove the level.
           if (empty($override_data[$key])) {
             unset($override_data[$key]);
diff --git a/core/modules/language/src/Config/LanguageConfigFactoryOverride.php b/core/modules/language/src/Config/LanguageConfigFactoryOverride.php
index b681618..ea48920 100644
--- a/core/modules/language/src/Config/LanguageConfigFactoryOverride.php
+++ b/core/modules/language/src/Config/LanguageConfigFactoryOverride.php
@@ -214,7 +214,7 @@ public function onConfigSave(ConfigCrudEvent $event) {
     foreach (\Drupal::languageManager()->getLanguages() as $language) {
       $config_translation = $this->getOverride($language->getId(), $name);
       if (!$config_translation->isNew()) {
-        static::filterOverride($config, $config_translation);
+        $this->filterOverride($config, $config_translation);
       }
     }
   }