diff --git a/functions.inc.php b/functions.inc.php
index 3e3b6e90..4626a396 100644
--- a/functions.inc.php
+++ b/functions.inc.php
@@ -1628,8 +1628,10 @@ function db_connection_string()
 
         if ($socket) {
             $dsn = "mysql:unix_socket={$socket};dbname={$database_name}";
-        } else {
+        } elseif ($CONF['database_port'] != null) {
             $dsn = "mysql:host={$CONF['database_host']};port={$CONF['database_port']};dbname={$database_name}";
+        } else {
+            $dsn = "mysql:host={$CONF['database_host']};dbname={$database_name}";
         }
     } elseif (db_sqlite()) {
         $db = $CONF['database_name'];