diff --git a/core/modules/language/src/Config/LanguageConfigFactoryOverrideInterface.php b/core/modules/language/src/Config/LanguageConfigFactoryOverrideInterface.php
index e79e90b..2cf4de9 100644
--- a/core/modules/language/src/Config/LanguageConfigFactoryOverrideInterface.php
+++ b/core/modules/language/src/Config/LanguageConfigFactoryOverrideInterface.php
@@ -14,8 +14,9 @@
   /**
    * Gets the language object used to override configuration data.
    *
-   * @return \Drupal\Core\Language\LanguageInterface
-   *   The language object used to override configuration data.
+   * @return \Drupal\Core\Language\LanguageInterface|null
+   *   The language object used to override configuration data or NULL, if not
+   *   set yet.
    */
   public function getLanguage();
 
diff --git a/core/modules/language/src/ConfigurableLanguageManager.php b/core/modules/language/src/ConfigurableLanguageManager.php
index 26892c3..41791f5 100644
--- a/core/modules/language/src/ConfigurableLanguageManager.php
+++ b/core/modules/language/src/ConfigurableLanguageManager.php
@@ -437,7 +437,8 @@ public function setConfigOverrideLanguage(LanguageInterface $language = NULL) {
    * {@inheritdoc}
    */
   public function getConfigOverrideLanguage() {
-    return $this->configFactoryOverride->getLanguage();
+    // There might be cases where the language override was not set yet.
+    return $this->configFactoryOverride->getLanguage() ?: $this->getCurrentLanguage();
   }
 
   /**
diff --git a/core/modules/language/tests/src/Unit/ConfigurableLanguageManagerTest.php b/core/modules/language/tests/src/Unit/ConfigurableLanguageManagerTest.php
new file mode 100644
index 0000000..88bec9d
--- /dev/null
+++ b/core/modules/language/tests/src/Unit/ConfigurableLanguageManagerTest.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace Drupal\Tests\language\Unit;
+
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageDefault;
+use Drupal\language\Config\LanguageConfigFactoryOverrideInterface;
+use Drupal\language\ConfigurableLanguageManager;
+use Drupal\Tests\UnitTestCase;
+use Symfony\Component\HttpFoundation\RequestStack;
+
+/**
+ * @coversDefaultClass \Drupal\language\ConfigurableLanguageManager
+ * @group language
+ */
+class ConfigurableLanguageManagerTest extends UnitTestCase {
+
+  /**
+   * @covers ::getConfigOverrideLanguage
+   */
+  public function testGetConfigOverrideLanguageWithMissingLanguage() {
+    $config_factory = $this->getConfigFactoryStub([]);
+    $module_handler = $this->prophesize(ModuleHandlerInterface::class);
+    $config_override = $this->prophesize(LanguageConfigFactoryOverrideInterface::class);
+    $config_override->getLanguage()->willReturn(NULL);
+    $language_manager = new ConfigurableLanguageManager(new LanguageDefault(['id' => 'en']), $config_factory, $module_handler->reveal(), $config_override->reveal(), new RequestStack());
+
+    $this->assertEquals('en', $language_manager->getConfigOverrideLanguage()->getId());
+  }
+
+  /**
+   * @covers ::getConfigOverrideLanguage
+   */
+  public function testGetConfigOverrideLanguageWithLanguage() {
+    $config_factory = $this->getConfigFactoryStub([]);
+    $module_handler = $this->prophesize(ModuleHandlerInterface::class);
+    $config_override = $this->prophesize(LanguageConfigFactoryOverrideInterface::class);
+    $config_override->getLanguage()->willReturn(new Language(['id' => 'fr']));
+    $language_manager = new ConfigurableLanguageManager(new LanguageDefault(['id' => 'en']), $config_factory, $module_handler->reveal(), $config_override->reveal(), new RequestStack());
+
+    $this->assertEquals('fr', $language_manager->getConfigOverrideLanguage()->getId());
+  }
+
+}