diff --git a/core/modules/language/src/Entity/ConfigurableLanguage.php b/core/modules/language/src/Entity/ConfigurableLanguage.php
index da4f839..31b5433 100644
--- a/core/modules/language/src/Entity/ConfigurableLanguage.php
+++ b/core/modules/language/src/Entity/ConfigurableLanguage.php
@@ -188,17 +188,15 @@ public static function postDelete(EntityStorageInterface $storage, array $entiti
       ConfigurableLanguageManager::rebuildServices();
     }
 
-    if ($language_manager instanceof ConfigurableLanguageManagerInterface) {
-      // Remove language from language prefix list.
-      $prefixes = language_negotiation_url_prefixes();
-      unset($prefixes[$language_manager->getid()]);
-      language_negotiation_url_prefixes_save($prefixes);
-
-      // Remove language from language domain list.
-      $domains = language_negotiation_url_domains();
-      unset($domains[$language_manager->id()]);
-      language_negotiation_url_domains_save($domains);
-    }
+    // Remove language from language prefix list.
+    $prefixes = language_negotiation_url_prefixes();
+    unset($prefixes[$language_manager->getCurrentLanguage()->getId()]);
+    language_negotiation_url_prefixes_save($prefixes);
+
+    // Remove language from language domain list.
+    $domains = language_negotiation_url_domains();
+    unset($domains[$language_manager->getCurrentLanguage()->getId()]);
+    language_negotiation_url_domains_save($domains);
   }
 
   /**