diff --git a/dibi/drivers/mysqli.php b/dibi/drivers/mysqli.php
index 6dc2b98d..6ec77e2b 100644
--- a/dibi/drivers/mysqli.php
+++ b/dibi/drivers/mysqli.php
@@ -197,7 +197,7 @@ class DibiMySqliDriver extends DibiObject implements IDibiDriver, IDibiResultDri
 	 */
 	public function getAffectedRows()
 	{
-		return mysqli_affected_rows($this->connection);
+		return mysqli_affected_rows($this->connection) === -1 ? FALSE : mysqli_affected_rows($this->connection);
 	}