diff --git a/Sources/Autoloader.php b/Sources/Autoloader.php
index 0a9ffacf16..7587143848 100644
--- a/Sources/Autoloader.php
+++ b/Sources/Autoloader.php
@@ -41,7 +41,7 @@
 	}
 
 	// Do any third-party scripts want in on the fun?
-	if (class_exists('SMF\\Config', false) && $hook_value !== (Config::$modSettings['integrate_autoload'] ?? '')) {
+	if (!defined('SMF_INSTALLING') && class_exists('SMF\\Config', false) && $hook_value !== (Config::$modSettings['integrate_autoload'] ?? '')) {
 		if (!class_exists('SMF\\IntegrationHook', false) && is_file($sourcedir . '/IntegrationHook.php')) {
 			require_once $sourcedir . '/IntegrationHook.php';
 		}
diff --git a/Sources/Db/APIs/MySQL.php b/Sources/Db/APIs/MySQL.php
index faa524c072..d3f7d473a0 100644
--- a/Sources/Db/APIs/MySQL.php
+++ b/Sources/Db/APIs/MySQL.php
@@ -1984,14 +1984,19 @@ protected function __construct(array $options = [])
 			$this->prefixReservedTables();
 		}
 
-		$this->get_version();
-		$this->supports_pcre = version_compare($this->version, strpos($this->version, 'MariaDB') !== false ? '10.0.5' : '8.0.4', '>=');
+		// At this point, if we don't have a connection, nothing else can be done.
+		if (empty($this->connection)) {
+			return;
+		}
 
 		// For backward compatibility.
 		if (!is_object(self::$db_connection)) {
 			self::$db_connection = $this->connection;
 		}
 
+		$this->get_version();
+		$this->supports_pcre = version_compare($this->version, strpos($this->version, 'MariaDB') !== false ? '10.0.5' : '8.0.4', '>=');
+
 		// Ensure database has UTF-8 as its default input charset.
 		$this->query(
 			'',
diff --git a/Sources/Db/APIs/PostgreSQL.php b/Sources/Db/APIs/PostgreSQL.php
index 3d5493c690..c668f5d4fa 100644
--- a/Sources/Db/APIs/PostgreSQL.php
+++ b/Sources/Db/APIs/PostgreSQL.php
@@ -2112,6 +2112,11 @@ protected function __construct(array $options = [])
 			ErrorHandler::displayDbError();
 		}
 
+		// At this point, if we don't have a connection, nothing else can be done.
+		if (empty($this->connection)) {
+			return;
+		}
+
 		// For backward compatibility.
 		if (!is_object(self::$db_connection)) {
 			self::$db_connection = $this->connection;
diff --git a/Sources/Db/DatabaseApi.php b/Sources/Db/DatabaseApi.php
index 53fc3504b4..752f69f63a 100644
--- a/Sources/Db/DatabaseApi.php
+++ b/Sources/Db/DatabaseApi.php
@@ -326,7 +326,27 @@ final public static function load(array $options = [])
 		}
 
 		// Figure out what type of database we are using.
-		switch (!empty(Config::$db_type) ? strtolower(Config::$db_type) : 'mysql') {
+		$class = self::getClass(!empty(Config::$db_type) ? strtolower(Config::$db_type) : 'mysql');
+
+		if (!class_exists(__NAMESPACE__ . '\\APIs\\' . $class)) {
+			ErrorHandler::displayDbError();
+		}
+
+		$class = __NAMESPACE__ . '\\APIs\\' . $class;
+		self::$db = new $class($options);
+
+		// Double check that we found what we expected.
+		if (!(self::$db instanceof DatabaseApi)) {
+			unset(self::$db);
+			ErrorHandler::displayDbError();
+		}
+
+		return self::$db;
+	}
+
+	public static function getClass($db_type)
+	{
+		switch (strtolower($db_type)) {
 			// PostgreSQL is known by many names.
 			case 'postgresql':
 			case 'postgres':
@@ -335,14 +355,14 @@ final public static function load(array $options = [])
 				$class = POSTGRE_TITLE;
 				break;
 
-				// MySQL and its forks.
+			// MySQL and its forks.
 			case 'mysql':
 			case 'mariadb':
 			case 'percona':
 				$class = MYSQL_TITLE;
 				break;
 
-				// Something else?
+			// Something else?
 			default:
 				$class = ucwords(Config::$db_type);
 
@@ -354,20 +374,7 @@ final public static function load(array $options = [])
 				break;
 		}
 
-		if (!class_exists(__NAMESPACE__ . '\\APIs\\' . $class)) {
-			ErrorHandler::displayDbError();
-		}
-
-		$class = __NAMESPACE__ . '\\APIs\\' . $class;
-		self::$db = new $class($options);
-
-		// Double check that we found what we expected.
-		if (!(self::$db instanceof DatabaseApi)) {
-			unset(self::$db);
-			ErrorHandler::displayDbError();
-		}
-
-		return self::$db;
+		return $class;
 	}
 
 	/**
diff --git a/other/install.php b/other/install.php
index b603e15cfb..e43c7b262c 100644
--- a/other/install.php
+++ b/other/install.php
@@ -254,7 +254,7 @@ function initialize_inputs()
 			foreach ($databases as $key => $dummy)
 			{
 				$type = ($key == 'mysqli') ? 'mysql' : $key;
-				$ftp->unlink('install_' . DB_SCRIPT_VERSION . '_' . $type . '.sql');
+				$ftp->unlink('install_' . DB_SCRIPT_VERSION . '_' . Db::getClass($type) . '.sql');
 			}
 
 			$ftp->close();
@@ -268,7 +268,7 @@ function initialize_inputs()
 			foreach ($databases as $key => $dummy)
 			{
 				$type = ($key == 'mysqli') ? 'mysql' : $key;
-				@unlink(Config::$boarddir . '/install_' . DB_SCRIPT_VERSION . '_' . $type . '.sql');
+				@unlink(Config::$boarddir . '/install_' . DB_SCRIPT_VERSION . '_' . Db::getClass($type) . '.sql');
 			}
 		}
 
@@ -479,11 +479,11 @@ function Welcome()
 		if ($db['supported'])
 		{
 			$type = ($key == 'mysqli') ? 'mysql' : $key;
-			if (!file_exists(Config::$boarddir . '/install_' . DB_SCRIPT_VERSION . '_' . $type . '.sql'))
+			if (!file_exists(Config::$boarddir . '/install_' . DB_SCRIPT_VERSION . '_' . Db::getClass($type) . '.sql'))
 			{
 				$databases[$key]['supported'] = false;
 				$notFoundSQLFile = true;
-				Lang::$txt['error_db_script_missing'] = sprintf(Lang::$txt['error_db_script_missing'], 'install_' . DB_SCRIPT_VERSION . '_' . $type . '.sql');
+				Lang::$txt['error_db_script_missing'] = sprintf(Lang::$txt['error_db_script_missing'], 'install_' . DB_SCRIPT_VERSION . '_' . Db::getClass($type) . '.sql');
 			}
 			else
 				$incontext['supported_databases'][] = $db;
@@ -868,9 +868,9 @@ function DatabaseSettings()
 		Config::load();
 
 		// Better find the database file!
-		if (!file_exists(Config::$sourcedir . '/Db/APIs/' . Config::$db_type . '.php'))
+		if (!file_exists(Config::$sourcedir . '/Db/APIs/' . Db::getClass(Config::$db_type) . '.php'))
 		{
-			$incontext['error'] = sprintf(Lang::$txt['error_db_file'], 'Db/APIs/' . Config::$db_type . '.php');
+			$incontext['error'] = sprintf(Lang::$txt['error_db_file'], 'Db/APIs/' . Db::getClass(Config::$db_type) . '.php');
 			return false;
 		}
 
@@ -1222,7 +1222,7 @@ function DatabasePopulation()
 
 	// Read in the SQL.  Turn this on and that off... internationalize... etc.
 	$type = (Config::$db_type == 'mysqli' ? 'mysql' : Config::$db_type);
-	$sql_lines = explode("\n", strtr(implode(' ', file(Config::$boarddir . '/install_' . DB_SCRIPT_VERSION . '_' . $type . '.sql')), $replaces));
+	$sql_lines = explode("\n", strtr(implode(' ', file(Config::$boarddir . '/install_' . DB_SCRIPT_VERSION . '_' . Db::getClass($type) . '.sql')), $replaces));
 
 	// Execute the SQL.
 	$current_statement = '';
diff --git a/other/install_2-1_mysql.sql b/other/install_2-1_MySQL.sql
similarity index 100%
rename from other/install_2-1_mysql.sql
rename to other/install_2-1_MySQL.sql
diff --git a/other/install_2-1_postgresql.sql b/other/install_2-1_PostgreSQL.sql
similarity index 100%
rename from other/install_2-1_postgresql.sql
rename to other/install_2-1_PostgreSQL.sql
diff --git a/other/upgrade.php b/other/upgrade.php
index 2defe17506..30a0b8e58e 100644
--- a/other/upgrade.php
+++ b/other/upgrade.php
@@ -733,7 +733,7 @@ function loadEssentialData()
 
 	require_once(Config::$sourcedir . '/Autoloader.php');
 
-	if (class_exists('SMF\\Db\\APIs\\' . Config::$db_type))
+	if (class_exists('SMF\\Db\\APIs\\' . Db::getClass(Config::$db_type)))
 	{
 		// Make the connection...
 		if (empty(Db::$db_connection))
@@ -782,10 +782,10 @@ function loadEssentialData()
 		Db::$db->free_result($request);
 	}
 	else
-		return throw_error(sprintf(Lang::$txt['error_sourcefile_missing'], 'Db/APIs/' . Config::$db_type . '.php'));
+		return die(sprintf(Lang::$txt['error_sourcefile_missing'], 'Db/APIs/' . Db::getClass(Config::$db_type) . '.php'));
 
 	// If they don't have the file, they're going to get a warning anyway so we won't need to clean request vars.
-	if (class_exists('SMF\\QueryString', false) && php_version_check())
+	if (class_exists('SMF\\QueryString') && php_version_check())
 	{
 		QueryString::cleanRequest();
 	}
@@ -815,8 +815,8 @@ function initialize_inputs()
 		// And the extra little files ;).
 		deleteFile(dirname(__FILE__) . '/upgrade_1-0.sql');
 		deleteFile(dirname(__FILE__) . '/upgrade_1-1.sql');
-		deleteFile(dirname(__FILE__) . '/upgrade_2-0_' . Config::$db_type . '.sql');
-		deleteFile(dirname(__FILE__) . '/upgrade_2-1_' . Config::$db_type . '.sql');
+		deleteFile(dirname(__FILE__) . '/upgrade_2-0_' . Db::getClass(Config::$db_type) . '.sql');
+		deleteFile(dirname(__FILE__) . '/upgrade_2-1_' . Db::getClass(Config::$db_type) . '.sql');
 		deleteFile(dirname(__FILE__) . '/upgrade-helper.php');
 
 		$dh = opendir(dirname(__FILE__));
@@ -873,12 +873,12 @@ function WelcomeLogin()
 	// Check for some key files - one template, one language, and a new and an old source file.
 	$check = @file_exists(Config::$modSettings['theme_dir'] . '/index.template.php')
 		&& @file_exists(Config::$sourcedir . '/QueryString.php')
-		&& @file_exists(Config::$sourcedir . '/Db/APIs/' . Config::$db_type . '.php')
-		&& @file_exists(dirname(__FILE__) . '/upgrade_2-1_' . Config::$db_type . '.sql');
+		&& @file_exists(Config::$sourcedir . '/Db/APIs/' . Db::getClass(Config::$db_type) . '.php')
+		&& @file_exists(dirname(__FILE__) . '/upgrade_2-1_' . Db::getClass(Config::$db_type) . '.sql');
 
 	// Need legacy scripts?
 	if (!isset(Config::$modSettings['smfVersion']) || Config::$modSettings['smfVersion'] < 2.1)
-		$check &= @file_exists(dirname(__FILE__) . '/upgrade_2-0_' . Config::$db_type . '.sql');
+		$check &= @file_exists(dirname(__FILE__) . '/upgrade_2-0_' . Db::getClass(Config::$db_type) . '.sql');
 	if (!isset(Config::$modSettings['smfVersion']) || Config::$modSettings['smfVersion'] < 2.0)
 		$check &= @file_exists(dirname(__FILE__) . '/upgrade_1-1.sql');
 	if (!isset(Config::$modSettings['smfVersion']) || Config::$modSettings['smfVersion'] < 1.1)
@@ -1677,8 +1677,8 @@ function DatabaseChanges()
 	$files = array(
 		array('upgrade_1-0.sql', '1.1', '1.1 RC0', false),
 		array('upgrade_1-1.sql', '2.0', '2.0 a', false),
-		array('upgrade_2-0_' . Config::$db_type . '.sql', '2.1', '2.1 dev0', false),
-		array('upgrade_2-1_' . Config::$db_type . '.sql', '3.0', SMF_VERSION, true),
+		array('upgrade_2-0_' . Db::getClass(Config::$db_type) . '.sql', '2.1', '2.1 dev0', false),
+		array('upgrade_2-1_' . Db::getClass(Config::$db_type) . '.sql', '3.0', SMF_VERSION, true),
 	);
 
 	// How many files are there in total?
@@ -4098,13 +4098,13 @@ function template_welcome_message()
 	{
 		$ago = time() - $upcontext['started'];
 		$ago_hours = floor($ago / 3600);
-		$ago_minutes = intval(($ago / 60) % 60);
+		$ago_minutes = (int) (((int) ($ago / 60)) % 60);
 		$ago_seconds = intval($ago % 60);
 		$agoTxt = $ago < 60 ? 'upgrade_time_s' : ($ago < 3600 ? 'upgrade_time_ms' : 'upgrade_time_hms');
 
 		$updated = time() - $upcontext['updated'];
 		$updated_hours = floor($updated / 3600);
-		$updated_minutes = intval(($updated / 60) % 60);
+		$updated_minutes = intval(((int) ($updated / 60)) % 60);
 		$updated_seconds = intval($updated % 60);
 		$updatedTxt = $updated < 60 ? 'upgrade_time_updated_s' : ($updated < 3600 ? 'upgrade_time_updated_hm' : 'upgrade_time_updated_hms');
 
diff --git a/other/upgrade_2-0_mysql.sql b/other/upgrade_2-0_MySQL.sql
similarity index 100%
rename from other/upgrade_2-0_mysql.sql
rename to other/upgrade_2-0_MySQL.sql
diff --git a/other/upgrade_2-0_postgresql.sql b/other/upgrade_2-0_PostgreSQL.sql
similarity index 100%
rename from other/upgrade_2-0_postgresql.sql
rename to other/upgrade_2-0_PostgreSQL.sql
diff --git a/other/upgrade_2-1_mysql.sql b/other/upgrade_2-1_MySQL.sql
similarity index 99%
rename from other/upgrade_2-1_mysql.sql
rename to other/upgrade_2-1_MySQL.sql
index 1d35c1c0b6..c7675628e5 100644
--- a/other/upgrade_2-1_mysql.sql
+++ b/other/upgrade_2-1_MySQL.sql
@@ -321,7 +321,7 @@ INSERT INTO {$db_prefix}settings (variable, value) VALUES ('defaultMaxListItems'
 	Db::$db->insert('replace',
 		'{db_prefix}settings',
 		array('variable' => 'string', 'value' => 'string'),
-		array('bcrypt_hash_cost', Security::hashVerifyPassword()),
+		array('bcrypt_hash_cost', Security::hashBenchmark()),
 		array('variable')
 	);
 ---}
diff --git a/other/upgrade_2-1_postgresql.sql b/other/upgrade_2-1_PostgreSQL.sql
similarity index 99%
rename from other/upgrade_2-1_postgresql.sql
rename to other/upgrade_2-1_PostgreSQL.sql
index 3285e2fa2e..e40d913292 100644
--- a/other/upgrade_2-1_postgresql.sql
+++ b/other/upgrade_2-1_PostgreSQL.sql
@@ -2089,7 +2089,7 @@ WHERE variable IN ('show_board_desc', 'display_quick_reply', 'show_mark_read', '
 	Db::$db->insert('replace',
 		'{db_prefix}settings',
 		array('variable' => 'string', 'value' => 'string'),
-		array('bcrypt_hash_cost', Security::hashVerifyPassword()),
+		array('bcrypt_hash_cost', Security::hashBenchmark()),
 		array('variable')
 	);
 ---}