diff --git a/src/PDO.php b/src/PDO.php
index 17d7124..fc13a51 100755
--- a/src/PDO.php
+++ b/src/PDO.php
@@ -12,12 +12,12 @@ class PDO extends NativePdo
      * Logged queries.
      * @var array<array>
      */
-    protected $log = [];
+    protected array $log = [];
 
     /**
      * @inheritDoc
      */
-    public function __construct($dsn, $username = null, $passwd = null, $options = null)
+    public function __construct(string $dsn, ?string $username = null, ?string $passwd = null, ?array $options = null)
     {
         parent::__construct($dsn, $username, $passwd, $options);
         $this->setAttribute(self::ATTR_STATEMENT_CLASS, [PDOStatement::class, [$this]]);
@@ -26,7 +26,7 @@ public function __construct($dsn, $username = null, $passwd = null, $options = n
     /**
      * @inheritDoc
      */
-    public function exec($statement)
+    public function exec(string $statement): int|false
     {
         $start = microtime(true);
         $result = parent::exec($statement);
@@ -38,7 +38,7 @@ public function exec($statement)
     /**
      * @inheritDoc
      */
-    public function query($statement, $mode = PDO::FETCH_ASSOC, ...$ctorargs)
+    public function query(string $statement, ?int $mode = PDO::FETCH_ASSOC, ...$ctorargs): PDOStatement|false
     {
         $start = microtime(true);
         $result = parent::query($statement, $mode, ...$ctorargs);
diff --git a/src/PDOStatement.php b/src/PDOStatement.php
index cf6e994..98ae8bd 100755
--- a/src/PDOStatement.php
+++ b/src/PDOStatement.php
@@ -27,12 +27,12 @@ protected function __construct(PDO $pdo)
      * @inheritDoc
      */
     public function bindParam(
-        $param,
-        &$var,
-        $type = PDO::PARAM_STR,
-        $maxLength = null,
-        $driverOptions = null
-    ) {
+        int|string $param,
+        mixed &$var,
+        int $type = PDO::PARAM_STR,
+        int $maxLength = 0,
+        mixed $driverOptions = null
+    ): bool {
         $this->bindings[$param] = $var;
         return parent::bindParam($param, $var, $type, $maxLength, $driverOptions);
     }
@@ -40,7 +40,7 @@ public function bindParam(
     /**
      * @inheritDoc
      */
-    public function bindValue($param, $value, $type = PDO::PARAM_STR)
+    public function bindValue(string|int $param, mixed $value, int $type = PDO::PARAM_STR): bool
     {
         $this->bindings[$param] = $value;
         return parent::bindValue($param, $value, $type);
@@ -49,7 +49,7 @@ public function bindValue($param, $value, $type = PDO::PARAM_STR)
     /**
      * @inheritDoc
      */
-    public function execute($params = null)
+    public function execute(?array $params = null): bool
     {
         if (is_array($params)) {
             $this->bindings = $params;
diff --git a/src/Tracy/BarPanel.php b/src/Tracy/BarPanel.php
index 1d23f1e..c2969ba 100755
--- a/src/Tracy/BarPanel.php
+++ b/src/Tracy/BarPanel.php
@@ -21,32 +21,25 @@ class BarPanel implements IBarPanel
 
     /**
      * Title
-     * @var string
      */
-    public $title = 'PDO logger';
+    public string $title = 'PDO logger';
 
     /**
      * Title HTML attributes
-     * @var string
      */
-    public $title_attributes = 'style="font-size:1.6em"';
+    public string $title_attributes = 'style="font-size:1.6em"';
 
     /**
      * Time table cell HTML attributes
-     * @var string
      */
-    public $time_attributes = 'style="font-weight:bold;color:#333;font-family:Courier New;font-size:1.1em"';
+    public string $time_attributes = 'style="font-weight:bold;color:#333;font-family:Courier New;font-size:1.1em"';
 
     /**
      * Query table cell HTML attributes
-     * @var string
      */
-    public $query_attributes = '';
+    public string $query_attributes = '';
 
-    /**
-     * @var PDO
-     */
-    private $pdo;
+    private PDO $pdo;
 
     public function __construct(PDO $pdo)
     {
@@ -55,18 +48,16 @@ public function __construct(PDO $pdo)
 
     /**
      * Get total queries execution time
-     * @return string
      */
-    protected function getTotalTime()
+    protected function getTotalTime(): string
     {
         return (string) round(array_sum(array_column($this->pdo->getLog(), 'time')), 4);
     }
 
     /**
      * Renders HTML code for custom tab.
-     * @return string
      */
-    public function getTab()
+    public function getTab(): string
     {
         $html = '<img src="'.$this->icon.'" alt="PDO queries logger" /> ';
         $queries = count($this->pdo->getLog());
@@ -86,7 +77,7 @@ public function getTab()
      * Renders HTML code for custom panel.
      * @return string
      */
-    public function getPanel()
+    public function getPanel(): string
     {
         if (class_exists('\SqlFormatter')) {
             \SqlFormatter::$pre_attributes = 'style="color: black;"';