diff -u b/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
--- b/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -185,8 +185,8 @@
  *     - description: (optional) A description of the module.
  *     - version: (optional) The version of the module.
  *     - links: (optional) Administration links provided by the module.
- *     - #requires: (optional) A list of modules that the project requires.
- *     - #required_by: (optional) A list of modules that require the project.
+ *     - #requires: A list of modules that the project requires.
+ *     - #required_by: A list of modules that require the project.
  *     - #attributes: A list of attributes for the module wrapper.
  */
 function template_preprocess_system_modules_details(&$variables) {