diff --git a/core/modules/migrate/src/Plugin/migrate/process/UrlEncode.php b/core/modules/migrate/src/Plugin/migrate/process/UrlEncode.php
index 2c3a78e..a9e8a22 100644
--- a/core/modules/migrate/src/Plugin/migrate/process/UrlEncode.php
+++ b/core/modules/migrate/src/Plugin/migrate/process/UrlEncode.php
@@ -18,10 +18,14 @@
  *
  * @code
  * process:
- *   plugin: urlencode
- *   source: some_url
+ *   new_url:
+ *     plugin: urlencode
+ *     source: 'http://example.com/a url with spaces.html'
  * @endcode
  *
+ * This will convert the source url 'http://example.com/a url with spaces.html'
+ * into 'http://example.com/a%20url%20with%20spaces.html'.
+ *
  * @see \Drupal\migrate\Plugin\MigrateProcessInterface
  *
  * @MigrateProcessPlugin(