diff --git a/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php b/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
index 4a6e461428..0a568093ba 100644
--- a/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
+++ b/core/modules/serialization/tests/src/Unit/Normalizer/NormalizerBaseTest.php
@@ -81,8 +81,8 @@ abstract class TestNormalizerBase extends NormalizerBase {
    * @param string $supported_interface_or_class
    *   The class name to set.
    */
-  public function setSupportedInterfaceOrClass($supported_interface_or_class, bool $is_cacheable = FALSE) {
-    $this->supportedTypes = [$supported_interface_or_class => $is_cacheable];
+  public function setSupportedInterfaceOrClass($supported_interface_or_class) {
+    $this->supportedTypes = [$supported_interface_or_class => FALSE];
   }
 
   /**