diff --git a/lib/private/Setup/MySQL.php b/lib/private/Setup/MySQL.php
index 920baf3e4ee10..2c16cac3d26e8 100644
--- a/lib/private/Setup/MySQL.php
+++ b/lib/private/Setup/MySQL.php
@@ -129,6 +129,7 @@ private function createDBUser($connection) {
 				'exception' => $ex,
 				'app' => 'mysql.setup',
 			]);
+			throw $ex;
 		}
 	}
 
@@ -138,6 +139,19 @@ private function createDBUser($connection) {
 	 * @return array
 	 */
 	private function createSpecificUser($username, $connection) {
+		$rootUser = $this->dbUser;
+		$rootPassword = $this->dbPassword;
+
+		//create a random password so we don't need to store the admin password in the config file
+		$saveSymbols = str_replace(['\"', '\\', '\'', '`'], '', ISecureRandom::CHAR_SYMBOLS);
+		$password = $this->random->generate(22, ISecureRandom::CHAR_ALPHANUMERIC . $saveSymbols)
+			. $this->random->generate(2, ISecureRandom::CHAR_UPPER)
+			. $this->random->generate(2, ISecureRandom::CHAR_LOWER)
+			. $this->random->generate(2, ISecureRandom::CHAR_DIGITS)
+			. $this->random->generate(2, $saveSymbols)
+		;
+		$this->dbPassword = str_shuffle($password);
+
 		try {
 			//user already specified in config
 			$oldUser = $this->config->getValue('dbuser', false);
@@ -160,10 +174,6 @@ private function createSpecificUser($username, $connection) {
 					if (count($data) === 0) {
 						//use the admin login data for the new database user
 						$this->dbUser = $adminUser;
-
-						//create a random password so we don't need to store the admin password in the config file
-						$this->dbPassword = $this->random->generate(30, ISecureRandom::CHAR_ALPHANUMERIC);
-
 						$this->createDBUser($connection);
 
 						break;
@@ -180,6 +190,9 @@ private function createSpecificUser($username, $connection) {
 				'exception' => $ex,
 				'app' => 'mysql.setup',
 			]);
+			// Restore the original credentials
+			$this->dbUser = $rootUser;
+			$this->dbPassword = $rootPassword;
 		}
 
 		$this->config->setValues([