diff --git a/administerusersbyrole.module b/administerusersbyrole.module
index 17b2cd0..55bdbd8 100644
--- a/administerusersbyrole.module
+++ b/administerusersbyrole.module
@@ -157,6 +157,41 @@ function administerusersbyrole_form_user_profile_form_alter(&$form, &$form_state
 }
 
 /**
+ * Implements hook_form_FORM_ID_alter().
+ *
+ * Make the user edit form consider our permissions when determining which
+ * elements should be visible to administrators.
+ */
+
+function administerusersbyrole_form_user_admin_account_alter(&$form, &$form_state) {
+
+ $form['#validate'][] = '_validate_user_block_n_unblock_permissions';
+}
+
+function _validate_user_block_n_unblock_permissions(&$form, &$form_state) {
+ global $user;
+
+ foreach (array_filter($form_state['input']['accounts']) as $uid => $value) {
+  $account = user_load($uid);
+
+  foreach ($account->roles as $rid => $role) {
+   if ($rid === DRUPAL_AUTHENTICATED_RID) {
+    continue;
+   }
+
+   if (user_access(_administerusersbyrole_build_perm_string($role, 'edit', TRUE))) {
+    return TRUE;
+   }
+   if (!user_access(_administerusersbyrole_build_perm_string($role, 'edit', FALSE))) {
+    if ($form_state['input']['operation'] == 'block' || $form_state['input']['operation'] == 'unblock') {
+     form_set_error($role, t('You do not have permission to block/unblock %user.', array('%user' => $account->name)));
+    }
+   }
+  }
+ }
+}
+
+/**
  * Generates a permission string for a given a role name.
  */
 function _administerusersbyrole_build_perm_string($role_name, $op = 'edit', $other = FALSE) {