diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 1cd473f2b5d..fe7750f6841 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -95,7 +95,7 @@ protected function _build_dsn()
 
 		$this->hostname === '' OR $this->dsn = 'host='.$this->hostname.' ';
 
-		if ( ! empty($this->port) && ctype_digit($this->port))
+		if ( ! empty($this->port) && ctype_digit((string) $this->port))
 		{
 			$this->dsn .= 'port='.$this->port.' ';
 		}