diff --git a/adminer/drivers/mysql.inc.php b/adminer/drivers/mysql.inc.php
index 53e0fdb52..a13152b5e 100644
--- a/adminer/drivers/mysql.inc.php
+++ b/adminer/drivers/mysql.inc.php
@@ -177,7 +177,7 @@ function attach(string $server, string $username, string $password): string {
 				}
 				list($host, $port) = host_port($server);
 				return $this->dsn(
-					"mysql:charset=utf8;host=$host" . ($port ? (is_numeric($port) ? ";port=" : ";unix_socket=") . $port : ""),
+					"mysql:charset=utf8".(!empty($host) ? ";host=$host" : '') . ($port ? (is_numeric($port) ? ";port=" : ";unix_socket=") . $port : ""),
 					$username,
 					$password,
 					$options
diff --git a/adminer/include/functions.inc.php b/adminer/include/functions.inc.php
index 9cc189e01..d418afb3f 100644
--- a/adminer/include/functions.inc.php
+++ b/adminer/include/functions.inc.php
@@ -839,7 +839,7 @@ function is_shortable(array $field): bool {
 function host_port(string $server) {
 	return (preg_match('~^(\[(.+)]|([^:]+)):([^:]+)$~', $server, $match) // [a:b] - IPv6
 		? array($match[2] . $match[3], $match[4])
-		: array($server, '')
+		: (preg_match('~^(\[(.+)]|([^:]+))$~', $server, $match) ? array($match[2] . $match[3], '') : explode(':', $server, 2)) // Match IPv6 or hostname without port, else split by first colon
 	);
 }