diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index d42326b..2349d83 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2735,6 +2735,7 @@ function drupal_installation_attempted() {
  * Use t() if your code will never run during the Drupal installation phase.
  * Use st() if your code will only run during installation and never any other
  * time. Use get_t() if your code could run in either circumstance.
+ * get_t() shouldn't be used in hook_update_N functions.
  *
  * @see t()
  * @see st()