diff --git a/src/Database/DBA.php b/src/Database/DBA.php
index 097f1b756a..e44260914e 100644
--- a/src/Database/DBA.php
+++ b/src/Database/DBA.php
@@ -421,7 +421,7 @@ class DBA
 	 * @param string|array  $table      Table name or array [schema => table]
 	 * @param array         $fields     contains the fields that are updated
 	 * @param array         $condition  condition array with the key values
-	 * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
+	 * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate, false = don't update identical fields)
 	 *
 	 * @return boolean was the update successfull?
 	 * @throws \Exception
diff --git a/src/Database/Database.php b/src/Database/Database.php
index 5b488e11f1..361a3248d9 100644
--- a/src/Database/Database.php
+++ b/src/Database/Database.php
@@ -1267,7 +1267,7 @@ class Database
 	 * @param string|array  $table      Table name or array [schema => table]
 	 * @param array         $fields     contains the fields that are updated
 	 * @param array         $condition  condition array with the key values
-	 * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
+	 * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate, false = don't update identical fields)
 	 *
 	 * @return boolean was the update successfull?
 	 * @throws \Exception