diff --git a/.gitignore b/.gitignore
index 88afc05..a1eadcd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 composer.lock
 test/
 vendor/
+/.idea/
diff --git a/composer.json b/composer.json
index 32b1bb6..b131334 100644
--- a/composer.json
+++ b/composer.json
@@ -18,7 +18,7 @@
         }
     ],
     "require": {
-        "php": ">=7.0.0"
+        "php": ">=8.0.0"
     },
     "autoload": {
         "psr-4": {
diff --git a/src/SessionHandler.php b/src/SessionHandler.php
index 1aa3160..127c107 100644
--- a/src/SessionHandler.php
+++ b/src/SessionHandler.php
@@ -5,25 +5,25 @@
 
 final class SessionHandler implements \SessionHandlerInterface
 {
-    private $dbConnection; # the mysqli connection
-    private $dbTable; # name of the db table to store sessions in
-    private $m_maxAge;
-
-
-    /**
-     * Create the session handler.
-     * @param \mysqli $mysqli - the database connection to store sessions in.
-     * @param string $tableName - the table within the database to store session data in.
-     * @param int $maxAge - the maximum age in seconds of a session variable.
-     */
-    public function __construct(\mysqli $mysqli, string $tableName, int $maxAge=86400)
-    {
-        $this->dbConnection = $mysqli;
-        $this->dbTable = $tableName;
-        $this->m_maxAge = $maxAge;
-
-        $createSessionsTableQuery =
-            "CREATE TABLE IF NOT EXISTS `{$this->dbTable}` (
+	private $dbConnection; # the mysqli connection
+	private $dbTable; # name of the db table to store sessions in
+	private $m_maxAge;
+
+
+	/**
+	 * Create the session handler.
+	 * @param \mysqli $mysqli - the database connection to store sessions in.
+	 * @param string $tableName - the table within the database to store session data in.
+	 * @param int $maxAge - the maximum age in seconds of a session variable.
+	 */
+	public function __construct(\mysqli $mysqli, string $tableName, int $maxAge=86400)
+	{
+		$this->dbConnection = $mysqli;
+		$this->dbTable = $tableName;
+		$this->m_maxAge = $maxAge;
+
+		$createSessionsTableQuery =
+			"CREATE TABLE IF NOT EXISTS `{$this->dbTable}` (
                 `id` varchar(32) NOT NULL,
                 `modified_timestamp` timestamp DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                 `data` mediumtext,
@@ -31,65 +31,66 @@ public function __construct(\mysqli $mysqli, string $tableName, int $maxAge=8640
                 KEY `modified_timestamp` (`modified_timestamp`)
             ) ENGINE=InnoDB DEFAULT CHARSET=utf8;";
 
-        $this->dbConnection->query($createSessionsTableQuery);
-    }
+		$this->dbConnection->query($createSessionsTableQuery);
+	}
 
 
-    public function open($savePath, $sessionName)
-    {
-        $sql = "DELETE FROM `{$this->dbTable}` WHERE `modified_timestamp` < (NOW() - INTERVAL {$this->m_maxAge} SECOND)";
-        return $this->dbConnection->query($sql);
-    }
+	public function open(string $savePath, string $sessionName) : bool
+	{
+		$sql = "DELETE FROM `{$this->dbTable}` WHERE `modified_timestamp` < (NOW() - INTERVAL {$this->m_maxAge} SECOND)";
+		return $this->dbConnection->query($sql);
+	}
 
 
-    public function close()
-    {
-        return $this->dbConnection->close();
-    }
+	public function close():bool
+	{
+		return $this->dbConnection->close();
+	}
 
 
-    public function read($id)
-    {
-        $sql = "SELECT `data` FROM `{$this->dbTable}` WHERE `id` = '{$id}'";
-        $result = $this->dbConnection->query($sql);
+	public function read($id):string|false
+	{
+		$sql = "SELECT `data` FROM `{$this->dbTable}` WHERE `id` = '{$id}'";
+		$result = $this->dbConnection->query($sql);
 
-        if ($result === false)
-        {
-            throw new \Exception("There is an issue with your session handler using MySQL.");
-        }
+		if ($result === false)
+		{
+			throw new \Exception("There is an issue with your session handler using MySQL.");
+		}
 
-        if ($result->num_rows === 0)
-        {
-            $result = "";
-        }
-        else
-        {
-            $row = $result->fetch_assoc();
-            $result = $row['data'];
-        }
+		if ($result->num_rows === 0)
+		{
+			$result = "";
+		}
+		else
+		{
+			$row = $result->fetch_assoc();
+			$result = $row['data'];
+			$result = $result === null ? "" : $result;
+		}
 
-        return $result;
-    }
+		return $result;
+	}
 
 
-    public function write($id, $data)
-    {
-        $sql = "REPLACE INTO `{$this->dbTable}` (id, data) VALUES('{$id}', '{$data}')";
-        return $this->dbConnection->query($sql);
-    }
+	public function write(string $id, string $data):bool
+	{
+		$sql = "REPLACE INTO `{$this->dbTable}` (id, data) VALUES('{$id}', '{$data}')";
+		return $this->dbConnection->query($sql);
+	}
 
 
-    public function destroy($id)
-    {
-        $sql = "DELETE FROM `{$this->dbTable}` WHERE `id` = '{$id}'";
-        return $this->dbConnection->query($sql);
-    }
+	public function destroy(string $id):bool
+	{
+		$sql = "DELETE FROM `{$this->dbTable}` WHERE `id` = '{$id}'";
+		return $this->dbConnection->query($sql);
+	}
 
 
-    public function gc($maxlifetime)
-    {
-        $minTime = time() - intval($maxlifetime);
-        $sql = "DELETE FROM `{$this->dbTable}` WHERE `timestamp` < '{$minTime}'";
-        return $this->dbConnection->query($sql);
-    }
-}
\ No newline at end of file
+	public function gc(int $maxlifetime):int|false
+	{
+		$minTime = time() - intval($maxlifetime);
+		$sql = "DELETE FROM `{$this->dbTable}` WHERE `modified_timestamp` < '{$minTime}'";
+		return $this->dbConnection->query($sql);
+	}
+}