diff --git a/esi.admin.inc b/esi.admin.inc
index d560582..3316fef 100644
--- a/esi.admin.inc
+++ b/esi.admin.inc
@@ -131,6 +131,19 @@ function esi_admin_settings_form() {
     '#description'    => t('Disabled - Do not use ESI. <br />Not Cached - Use ESI, but never cache the content. <br />Global - Content is same on every page. <br />Page - Content changes based on the URL. <br />User Role - Content changes based on the user role. <br />User Role/Page - Content changes based on the user role as well as the URL. <br />User ID - Content changes based on the UID; otherwise it is the same as global. <br />User ID/Page - Content changes based on the UID and based on the URL.'),
   );
 
+  // Roles config
+  $form['roles'] = array(
+    '#type' => 'fieldset',
+    '#title' => t('Role settings'),
+  );
+  $form['roles']['esi_include_roles'] = array(
+    '#title' => t('Roles included in User Role scope'),
+    '#type' => 'checkboxes',
+    '#options' => user_roles(FALSE),
+    '#default_value' => variable_get('esi_include_roles', array()),
+    '#description' => t('Choose the roles that will be included in the roles hash. Only select roles that may affect caching. If you select no roles, all roles will be candidates.'),
+  );
+
   // Cache Flusing
   $form['cache_page'] = array(
     '#type'         => 'fieldset',
diff --git a/esi.inc b/esi.inc
index 6c94504..48bef52 100644
--- a/esi.inc
+++ b/esi.inc
@@ -51,11 +51,19 @@ function _esi__get_roles_hash($rids = NULL) {
     global $user;
     $rids = !empty($user->roles) ? array_keys($user->roles) : 0;
   }
+  $include_roles = array_filter(variable_get('esi_include_roles', array()));
+  if (!empty($include_roles)) {
+    $included_rids = array_intersect($rids, $include_roles);
+  }
+  else {
+    $included_rids = $rids;
+  }
 
-  $hash = implode(':', $rids);
+  $hash = implode(':', $included_rids);
   if (!isset($roles[$hash])) {
     $seed = _esi__get_seed_key();
     $roles[$hash] = md5($seed . md5($hash));
+    drupal_alter('esi_roles_hash', $roles[$hash], $included_rids, $rids, $seed);
   }
   return $roles[$hash];
 }
@@ -77,6 +85,7 @@ function esi_get_user_hash($uid = NULL) {
   if (!isset($users[$uid])) {
     $seed = _esi__get_seed_key();
     $users[$uid] = md5($seed . md5($uid));
+    drupal_alter('esi_user_hash', $users[$uid], $uid, $seed);
   }
   return $users[$uid];
 }