diff --git a/devel.admin.inc b/devel.admin.inc
index 3c4dbdb..586d527 100644
--- a/devel.admin.inc
+++ b/devel.admin.inc
@@ -105,6 +105,11 @@ function devel_admin_settings() {
     '#default_value' => variable_get('devel_page_alter', FALSE),
     '#description' => t('Display $page array from <a href="http://api.drupal.org/api/function/hook_page_alter/7">hook_page_alter()</a> in the messages area of each page.'),
   );
+  $form['devel_perm_names'] = array('#type' => 'checkbox',
+    '#title' => t('Display machine names of permissions'),
+    '#default_value' => variable_get('devel_perm_names', FALSE),
+    '#description' => t('Display the language-independent machine names of the permissions in mouse-over hints on the !Permissions page; also display the module base file names.', array('!Permissions' => l(t('Permissions'), 'admin/people/permissions'))),
+  );
 
   $error_handlers = devel_get_handlers();
   $form['devel_error_handlers'] = array(
diff --git a/devel.module b/devel.module
index 5143fa6..8cc5691 100644
--- a/devel.module
+++ b/devel.module
@@ -1895,3 +1895,22 @@ function devel_rebuild_node_comment_statistics() {
     ->from($query)
     ->execute();
 }
+
+/**
+ * Implements hook_form_alter().
+ *
+ * Adds mouse-over hints on the Permissions page to display
+ * language-independent machine names.
+ */
+function devel_form_user_admin_permissions_alter(&$form, &$form_state) {
+  if (user_access('access devel information') && variable_get('devel_perm_names', FALSE)) {
+    foreach ($form['permission'] as $perm => $data) {
+      if (is_numeric($perm)) {
+        $form['permission'][$perm]['#markup'] = '<span title="' . $form['permission'][$perm]['#id'] . '">' . $form['permission'][$perm]['#markup'] . '</span>';
+      }
+      else {
+        $form['permission'][$perm]['#markup'] = '<span title="' . check_plain($perm) . '">' . $form['permission'][$perm]['#markup'] . '</span>';
+      }
+    }
+  }
+}