diff --git a/src/main/php/com/handlebarsjs/BlockNode.class.php b/src/main/php/com/handlebarsjs/BlockNode.class.php
index f930b46..78eba3f 100755
--- a/src/main/php/com/handlebarsjs/BlockNode.class.php
+++ b/src/main/php/com/handlebarsjs/BlockNode.class.php
@@ -19,14 +19,14 @@ class BlockNode extends Node {
   /**
    * Creates a new section node
    *
-   * @param string $name
-   * @param var[] $options
-   * @param com.github.mustache.NodeList $fn
-   * @param com.github.mustache.NodeList $inverse
-   * @param string $start
-   * @param string $end
+   * @param  string $name
+   * @param  var[] $options
+   * @param  ?com.github.mustache.NodeList $fn
+   * @param  ?com.github.mustache.NodeList $inverse
+   * @param  string $start
+   * @param  string $end
    */
-  public function __construct($name, $options= [], NodeList $fn= null, NodeList $inverse= null, $start= '{{', $end= '}}') {
+  public function __construct($name, $options= [], $fn= null, $inverse= null, $start= '{{', $end= '}}') {
     $this->name= $name;
     $this->options= $options;
     $this->fn= $fn ?? new NodeList();
diff --git a/src/main/php/com/handlebarsjs/EachBlockHelper.class.php b/src/main/php/com/handlebarsjs/EachBlockHelper.class.php
index 795f7d7..53d8303 100755
--- a/src/main/php/com/handlebarsjs/EachBlockHelper.class.php
+++ b/src/main/php/com/handlebarsjs/EachBlockHelper.class.php
@@ -11,13 +11,13 @@ class EachBlockHelper extends BlockNode {
   /**
    * Creates a new with block helper
    *
-   * @param string[] $options
-   * @param com.github.mustache.NodeList $fn
-   * @param com.github.mustache.NodeList $inverse
-   * @param string $start
-   * @param string $end
+   * @param  string[] $options
+   * @param  ?com.github.mustache.NodeList $fn
+   * @param  ?com.github.mustache.NodeList $inverse
+   * @param  string $start
+   * @param  string $end
    */
-  public function __construct($options= [], NodeList $fn= null, NodeList $inverse= null, $start= '{{', $end= '}}') {
+  public function __construct($options= [], $fn= null, $inverse= null, $start= '{{', $end= '}}') {
     parent::__construct('each', $options, $fn, $inverse, $start, $end);
     $this->params= isset($options[1]) ? cast($options[1], BlockParams::class)->names : [];
   }
diff --git a/src/main/php/com/handlebarsjs/HandlebarsEngine.class.php b/src/main/php/com/handlebarsjs/HandlebarsEngine.class.php
index ef173d3..9b8220a 100755
--- a/src/main/php/com/handlebarsjs/HandlebarsEngine.class.php
+++ b/src/main/php/com/handlebarsjs/HandlebarsEngine.class.php
@@ -35,8 +35,12 @@ static function __static() {
     ];
   }
 
-  /** Create new instance and initialize builtin helpers */
-  public function __construct(HandlebarsParser $parser= null) {
+  /**
+   * Create new instance and initialize builtin helpers
+   *
+   * @param  ?com.handlebarsjs.HandlebarsParser $parser
+   */
+  public function __construct($parser= null) {
     $this->parser= $parser ?? new HandlebarsParser();
     $this->templates= new Templates();
     $this->helpers= self::$builtin;
diff --git a/src/main/php/com/handlebarsjs/IfBlockHelper.class.php b/src/main/php/com/handlebarsjs/IfBlockHelper.class.php
index 7340177..dc914b5 100755
--- a/src/main/php/com/handlebarsjs/IfBlockHelper.class.php
+++ b/src/main/php/com/handlebarsjs/IfBlockHelper.class.php
@@ -10,13 +10,13 @@ class IfBlockHelper extends BlockNode {
   /**
    * Creates a new with block helper
    *
-   * @param string[] $options
-   * @param com.github.mustache.NodeList $fn
-   * @param com.github.mustache.NodeList $inverse
-   * @param string $start
-   * @param string $end
+   * @param  string[] $options
+   * @param  ?com.github.mustache.NodeList $fn
+   * @param  ?com.github.mustache.NodeList $inverse
+   * @param  string $start
+   * @param  string $end
    */
-  public function __construct($options= [], NodeList $fn= null, NodeList $inverse= null, $start= '{{', $end= '}}') {
+  public function __construct($options= [], $fn= null, $inverse= null, $start= '{{', $end= '}}') {
     parent::__construct('if', $options, $fn, $inverse, $start, $end);
   }
 
diff --git a/src/main/php/com/handlebarsjs/PartialBlockHelper.class.php b/src/main/php/com/handlebarsjs/PartialBlockHelper.class.php
index a1b09f5..9b452d9 100755
--- a/src/main/php/com/handlebarsjs/PartialBlockHelper.class.php
+++ b/src/main/php/com/handlebarsjs/PartialBlockHelper.class.php
@@ -13,13 +13,13 @@ class PartialBlockHelper extends BlockNode {
   /**
    * Creates a new with block helper
    *
-   * @param string[] $options
-   * @param com.github.mustache.NodeList $fn
-   * @param com.github.mustache.NodeList $inverse
-   * @param string $start
-   * @param string $end
+   * @param  string[] $options
+   * @param  ?com.github.mustache.NodeList $fn
+   * @param  ?com.github.mustache.NodeList $inverse
+   * @param  string $start
+   * @param  string $end
    */
-  public function __construct($options= [], NodeList $fn= null, NodeList $inverse= null, $start= '{{', $end= '}}') {
+  public function __construct($options= [], $fn= null, $inverse= null, $start= '{{', $end= '}}') {
     $template= (string)array_shift($options);
     parent::__construct($template, $options, $fn, $inverse, $start, $end);
   }
diff --git a/src/main/php/com/handlebarsjs/UnlessBlockHelper.class.php b/src/main/php/com/handlebarsjs/UnlessBlockHelper.class.php
index c8c0f7e..b029388 100755
--- a/src/main/php/com/handlebarsjs/UnlessBlockHelper.class.php
+++ b/src/main/php/com/handlebarsjs/UnlessBlockHelper.class.php
@@ -10,13 +10,13 @@ class UnlessBlockHelper extends BlockNode {
   /**
    * Creates a new with block helper
    *
-   * @param string[] $options
-   * @param com.github.mustache.NodeList $fn
-   * @param com.github.mustache.NodeList $inverse
-   * @param string $start
-   * @param string $end
+   * @param  string[] $options
+   * @param  ?com.github.mustache.NodeList $fn
+   * @param  ?com.github.mustache.NodeList $inverse
+   * @param  string $start
+   * @param  string $end
    */
-  public function __construct($options= [], NodeList $fn= null, NodeList $inverse= null, $start= '{{', $end= '}}') {
+  public function __construct($options= [], $fn= null, $inverse= null, $start= '{{', $end= '}}') {
     parent::__construct('unless', $options, $fn, $inverse, $start, $end);
   }
 
diff --git a/src/main/php/com/handlebarsjs/WithBlockHelper.class.php b/src/main/php/com/handlebarsjs/WithBlockHelper.class.php
index bd2c173..b5c1040 100755
--- a/src/main/php/com/handlebarsjs/WithBlockHelper.class.php
+++ b/src/main/php/com/handlebarsjs/WithBlockHelper.class.php
@@ -11,13 +11,13 @@ class WithBlockHelper extends BlockNode {
   /**
    * Creates a new with block helper
    *
-   * @param string[] $options
-   * @param com.github.mustache.NodeList $fn
-   * @param com.github.mustache.NodeList $inverse
-   * @param string $start
-   * @param string $end
+   * @param  string[] $options
+   * @param  ?com.github.mustache.NodeList $fn
+   * @param  ?com.github.mustache.NodeList $inverse
+   * @param  string $start
+   * @param  string $end
    */
-  public function __construct($options= [], NodeList $fn= null, NodeList $inverse= null, $start= '{{', $end= '}}') {
+  public function __construct($options= [], $fn= null, $inverse= null, $start= '{{', $end= '}}') {
     parent::__construct('with', $options, $fn, $inverse, $start, $end);
     $this->alias= isset($options[1]) ? cast($options[1], BlockParams::class)->names[0] : null;
   }