diff --git a/adminer/drivers/mysql.inc.php b/adminer/drivers/mysql.inc.php
index 4dc0cc19..4d704fc5 100644
--- a/adminer/drivers/mysql.inc.php
+++ b/adminer/drivers/mysql.inc.php
@@ -238,11 +238,15 @@ if (!defined("DRIVER")) {
 				$options = array(PDO::MYSQL_ATTR_LOCAL_INFILE => false);
 				$ssl = $adminer->connectSsl();
 				if ($ssl) {
-					$options += array(
-						PDO::MYSQL_ATTR_SSL_KEY => $ssl['key'],
-						PDO::MYSQL_ATTR_SSL_CERT => $ssl['cert'],
-						PDO::MYSQL_ATTR_SSL_CA => $ssl['ca'],
-					);
+					if (!empty($ssl['key'])) {
+						$options[PDO::MYSQL_ATTR_SSL_KEY] = $ssl['key'];
+					}
+					if (!empty($ssl['cert'])) {
+						$options[PDO::MYSQL_ATTR_SSL_CERT] = $ssl['cert'];
+					}
+					if (!empty($ssl['ca'])) {
+						$options[PDO::MYSQL_ATTR_SSL_CA] = $ssl['ca'];
+					}
 				}
 				$this->dsn(
 					"mysql:charset=utf8;host=" . str_replace(":", ";unix_socket=", preg_replace('~:(\d)~', ';port=\1', $server)),