diff --git a/core/themes/claro/templates/admin/update-version.html.twig b/core/themes/claro/templates/admin/update-version.html.twig
index d9aebbb88f..91c3a29ff0 100644
--- a/core/themes/claro/templates/admin/update-version.html.twig
+++ b/core/themes/claro/templates/admin/update-version.html.twig
@@ -3,6 +3,7 @@
  * @file
  * Theme override for the version display of a project.
  *
+ * Available variables:
  * - attributes: HTML attributes suitable for a container element.
  * - title: The title of the project.
  * - core_compatibility_details: Render array of core compatibility details.
diff --git a/core/themes/stable/templates/admin/update-version.html.twig b/core/themes/stable/templates/admin/update-version.html.twig
index 41754fd700..e8c3433d5e 100644
--- a/core/themes/stable/templates/admin/update-version.html.twig
+++ b/core/themes/stable/templates/admin/update-version.html.twig
@@ -3,6 +3,7 @@
  * @file
  * Theme override for the version display of a project.
  *
+ * Available variables:
  * - attributes: HTML attributes suitable for a container element.
  * - title: The title of the project.
  * - core_compatibility_details: Render array of core compatibility details.