diff --git a/reference/pdo/pdostatement/rowcount.xml b/reference/pdo/pdostatement/rowcount.xml
index 1889c8e6f36f..211cd03224ff 100644
--- a/reference/pdo/pdostatement/rowcount.xml
+++ b/reference/pdo/pdostatement/rowcount.xml
@@ -20,9 +20,10 @@
executed by the corresponding PDOStatement object.
- If the last SQL statement executed by the associated
- PDOStatement was a SELECT statement, some databases
- may return the number of rows returned by that statement. However, this
+ For statements that produce result sets, such as SELECT,
+ the behavior is undefined and can be different for each driver.
+ Some databases may return the number of rows produced by that statement
+ (e.g. MySQL in buffered mode), but this
behaviour is not guaranteed for all databases and should not be relied
on for portable applications.