diff --git a/src/Changes/Changes.php b/src/Changes/Changes.php
index ba9517e..2a0372b 100644
--- a/src/Changes/Changes.php
+++ b/src/Changes/Changes.php
@@ -88,7 +88,7 @@ class Changes implements ChangesInterface {
   /**
    * {@inheritdoc}
    */
-  public function parameters(ParameterBag $parameters) {
+  public function parameters(ParameterBag $parameters = NULL) {
     $this->parameters = $parameters;
     return $this;
   }
diff --git a/src/Changes/ChangesInterface.php b/src/Changes/ChangesInterface.php
index d964e04..1b42b86 100644
--- a/src/Changes/ChangesInterface.php
+++ b/src/Changes/ChangesInterface.php
@@ -35,7 +35,7 @@ interface ChangesInterface {
    * @return \Drupal\replication\Changes\ChangesInterface
    *   Returns $this.
    */
-  public function parameters(ParameterBag $parameters);
+  public function parameters(ParameterBag $parameters = NULL);
 
   /**
    * Set the flag for including entities in the changeset.