diff --git a/core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php b/core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php
index cc37d2d..2285eab 100644
--- a/core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php
+++ b/core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php
@@ -30,7 +30,7 @@ public function getDefinition($plugin_id, $exception_on_invalid = TRUE) {
    * @param string $plugin_id
    *   A plugin id.
    * @param bool $exception_on_invalid
-   *   If TRUE, an invalid plugin ID will throw an exception.
+   *   If TRUE, an invalid plugin ID will cause an exception to be thrown; if FALSE, NULL will be returned.
    *
    * @return array|null
    *   A plugin definition, or NULL if the plugin ID is invalid and