diff --git a/src/Auth.php b/src/Auth.php
index 0e73418..0c9013e 100644
--- a/src/Auth.php
+++ b/src/Auth.php
@@ -33,8 +33,6 @@ final class Auth extends UserManager {
 	const THROTTLE_ACTION_CONSUME_TOKEN = 'confirm_email';
 	const HTTP_STATUS_CODE_TOO_MANY_REQUESTS = 429;
 
-	/** @var PdoDatabase the database connection that will be used */
-	private $db;
 	/** @var boolean whether HTTPS (TLS/SSL) will be used (recommended) */
 	private $useHttps;
 	/** @var boolean whether cookies should be accessible via client-side scripts (*not* recommended) */
@@ -47,24 +45,13 @@ final class Auth extends UserManager {
 	private $throttlingTimeBucketSize;
 
 	/**
-	 * @param PdoDatabase|PdoDsn|\PDO $databaseConnection the database connection that will be used
+	 * @param PdoDatabase|PdoDsn|\PDO $databaseConnection the database connection to operate on
 	 * @param bool $useHttps whether HTTPS (TLS/SSL) will be used (recommended)
 	 * @param bool $allowCookiesScriptAccess whether cookies should be accessible via client-side scripts (*not* recommended)
 	 * @param string $ipAddress the IP address that should be used instead of the default setting (if any), e.g. when behind a proxy
 	 */
 	public function __construct($databaseConnection, $useHttps = false, $allowCookiesScriptAccess = false, $ipAddress = null) {
-		if ($databaseConnection instanceof PdoDatabase) {
-			$this->db = $databaseConnection;
-		}
-		elseif ($databaseConnection instanceof PdoDsn) {
-			$this->db = PdoDatabase::fromDsn($databaseConnection);
-		}
-		elseif ($databaseConnection instanceof \PDO) {
-			$this->db = PdoDatabase::fromPdo($databaseConnection, true);
-		}
-		else {
-			throw new \InvalidArgumentException('The database connection must be an instance of either `PdoDatabase`, `PdoDsn` or `PDO`');
-		}
+		parent::__construct($databaseConnection);
 
 		$this->useHttps = $useHttps;
 		$this->allowCookiesScriptAccess = $allowCookiesScriptAccess;
diff --git a/src/UserManager.php b/src/UserManager.php
index f488907..bb00c2a 100644
--- a/src/UserManager.php
+++ b/src/UserManager.php
@@ -8,5 +8,33 @@
 
 namespace Delight\Auth;
 
+use Delight\Db\PdoDatabase;
+use Delight\Db\PdoDsn;
+
 /** Abstract base class for components implementing user management */
-abstract class UserManager {}
+abstract class UserManager {
+
+	/** @var PdoDatabase the database connection to operate on */
+	protected $db;
+
+	/**
+	 * @param PdoDatabase|PdoDsn|\PDO $databaseConnection the database connection to operate on
+	 */
+	protected function __construct($databaseConnection) {
+		if ($databaseConnection instanceof PdoDatabase) {
+			$this->db = $databaseConnection;
+		}
+		elseif ($databaseConnection instanceof PdoDsn) {
+			$this->db = PdoDatabase::fromDsn($databaseConnection);
+		}
+		elseif ($databaseConnection instanceof \PDO) {
+			$this->db = PdoDatabase::fromPdo($databaseConnection, true);
+		}
+		else {
+			$this->db = null;
+
+			throw new \InvalidArgumentException('The database connection must be an instance of either `PdoDatabase`, `PdoDsn` or `PDO`');
+		}
+	}
+
+}