diff --git a/metatag.api.php b/metatag.api.php
index 59a37f9..f356140 100644
--- a/metatag.api.php
+++ b/metatag.api.php
@@ -439,8 +439,8 @@ function hook_metatag_i18n_context_alter(&$context, $tag_name) {
 /**
  * Allow modules to overide the expiration of metatag caches.
  *
- * By default Metatag caches everything as CACHE_PERMANENT,
- * this alter allows to change that.
+ * By default Metatag caches everything as CACHE_PERMANENT, this alter allows to
+ * change that.
  *
  * @param $expire
  *   The expire value to change.
diff --git a/metatag.module b/metatag.module
index 91c2613..a197489 100644
--- a/metatag.module
+++ b/metatag.module
@@ -2657,9 +2657,10 @@ function metatag_cache_default_cid_parts(array $cid_parts = array()) {
  * @see cache_set()
  */
 function metatag_cache_set($cid, $data) {
-  // Cache the data for later.
+  // By default the cached data will not expire.
   $expire = CACHE_PERMANENT;
-  //Triggers hook_metatag_cache_setexpire_alter().
+
+  // Triggers hook_metatag_cache_set_expire_alter().
   drupal_alter("metatag_cache_set_expire", $expire, $cid, $data);
   return cache_set($cid, $data, 'cache_metatag', $expire);
 }