diff --git a/includes/database.mysql-common.inc b/includes/database.mysql-common.inc
index e3e0d85d533759684a609e9887017cc6004c0245..ead7f367c94fb9769dda581cf1d675958a364716 100644
--- a/includes/database.mysql-common.inc
+++ b/includes/database.mysql-common.inc
@@ -26,8 +26,9 @@
  *   and TRUE values to decimal 1.
  *
  * @return
- *   A database query result resource, or FALSE if the query was not
- *   executed correctly.
+ *   Successful SELECT, SHOW, DESCRIBE, EXPLAIN, or other queries which return a
+ *   set of results will return a database query result resource. Other
+ *   successful queries will return TRUE and failing queries will return FALSE.
  */
 function db_query($query) {
   $args = func_get_args();