diff --git a/composer.json b/composer.json
index ec22aef..e4a6d46 100644
--- a/composer.json
+++ b/composer.json
@@ -2,6 +2,7 @@
     "name": "react-parallel/stubs",
     "description": "\ud83e\udecf Stubs (for PHPstan)",
     "license": "MIT",
+    "type": "phpstan-extension",
     "authors": [
         {
             "name": "Cees-Jan Kiewiet",
@@ -28,6 +29,13 @@
         },
         "sort-packages": true
     },
+    "extra": {
+        "phpstan": {
+            "includes": [
+                "extension.neon"
+            ]
+        }
+    },
     "scripts": {
         "post-install-cmd": [
             "composer normalize"
diff --git a/composer.lock b/composer.lock
index 124cebc..77c0699 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "56ae7d81123870be93be396f5e50f59e",
+    "content-hash": "592a214dff3265542af78d7bfb7c02ed",
     "packages": [],
     "packages-dev": [
         {
diff --git a/extension.neon b/extension.neon
new file mode 100644
index 0000000..3d7cd60
--- /dev/null
+++ b/extension.neon
@@ -0,0 +1,6 @@
+parameters:
+	stubFiles:
+		- stubs/Channel.stub
+		- stubs/Event.stub
+		- stubs/functions.stub
+		- stubs/Future.stub
diff --git a/stubs/Channel.stub b/stubs/Channel.stub
index 832375c..184e27a 100644
--- a/stubs/Channel.stub
+++ b/stubs/Channel.stub
@@ -1,10 +1,10 @@
 <?php
 
-declare(strict_types=1);
-
 namespace parallel;
 
-/** @template T */
+/**
+ * @template T
+ */
 final class Channel
 {
     /**
@@ -18,11 +18,9 @@ final class Channel
      * Shall make an anonymous unbuffered channel
      * Shall make an anonymous buffered channel with the given capacity
      *
-     * @param int|null $capacity May be Channel::Infinite or a positive integer
+     * @param null|int $capacity May be Channel::Infinite or a positive integer
      */
-    public function __construct(int|null $capacity = null)
-    {
-    }
+    public function __construct(?int $capacity = null) {}
 
     /* Access */
 
@@ -30,68 +28,55 @@ final class Channel
      * Shall make an unbuffered channel with the given name
      * Shall make a buffered channel with the given name and capacity
      *
-     * @param string   $name     The name of the channel.
-     * @param int|null $capacity May be Channel::Infinite or a positive integer
+     * @param string $name     The name of the channel.
+     * @param null|int $capacity May be Channel::Infinite or a positive integer
      *
      * @return Channel<T>
      *
      * @throws Channel\Error\Existence if channel already exists.
      */
-    public static function make(string $name, int|null $capacity = null): Channel
-    {
-    }
+    public static function make(string $name, ?int $capacity = null): Channel {}
 
     /**
      * Shall open the channel with the given name
      *
+     * @param string $name
      * @return Channel<T>
      *
      * @throws Channel\Error\Existence if channel does not exist.
      */
-    public static function open(string $name): Channel
-    {
-    }
+    public static function open(string $name): Channel {}
 
     /* Sharing */
 
     /**
      * Shall send the given value on this channel
-     *
      * @param T $value
      *
      * @throws Channel\Error\Closed if channel is closed.
      * @throws Channel\Error\IllegalValue if value is illegal.
      */
-    public function send($value): void
-    {
-    }
+    public function send($value): void {}
 
     /**
      * Shall recv a value from this channel
-     *
      * @return T
      *
      * @throws Channel\Error\Closed if channel is closed.
      */
-    public function recv()
-    {
-    }
+    public function recv() {}
 
     /* Closing */
 
     /**
      * Shall close this channel
-     *
      * @throws Channel\Error\Closed if channel is closed.
      */
-    public function close(): void
-    {
-    }
+    public function close(): void {}
 
     /**
      * Returns name of channel
+     * @return string
      */
-    public function __toString(): string
-    {
-    }
+    public function __toString(): string {}
 }
diff --git a/stubs/Event.stub b/stubs/Event.stub
index 469de0c..364149a 100644
--- a/stubs/Event.stub
+++ b/stubs/Event.stub
@@ -1,35 +1,35 @@
 <?php
 
-declare(strict_types=1);
-
 namespace parallel\Events;
 
 use parallel\Channel;
 use parallel\Future;
 
-/** @template T */
+/**
+ * @template T
+ */
 final class Event
 {
     /**
      * Shall be one of Event\Type constants
+     * @var int
      */
-    public int $type;
+    public $type;
 
     /**
      * Shall be the source of the event (target name)
+     * @var string
      */
-    public string $source;
+    public $source;
 
     /**
      * Shall be either Future or Channel
-     *
      * @var Future<T>|Channel<T>
      */
-    public Future|Channel $object;
+    public $object;
 
     /**
      * Shall be set for Read/Error events
-     *
      * @var T
      */
     public $value;
diff --git a/stubs/Future.stub b/stubs/Future.stub
index 888c31a..b8f96df 100644
--- a/stubs/Future.stub
+++ b/stubs/Future.stub
@@ -1,12 +1,12 @@
 <?php
 
-declare(strict_types=1);
-
 namespace parallel;
 
 use Throwable;
 
-/** @template T */
+/**
+ * @template T
+ */
 final class Future
 {
     /* Resolution */
@@ -22,25 +22,21 @@ final class Future
      * @throws Future\Error\Foreign if task raised an unrecognized uncaught exception.
      * @throws Throwable Shall rethrow \Throwable uncaught in task
      */
-    public function value()
-    {
-    }
+    public function value() {}
 
     /* State */
 
     /**
      * Shall indicate if the task is completed
+     * @return bool
      */
-    public function done(): bool
-    {
-    }
+    public function done(): bool {}
 
     /**
      * Shall indicate if the task was cancelled
+     * @return bool
      */
-    public function cancelled(): bool
-    {
-    }
+    public function cancelled(): bool {}
 
     /* Cancellation */
 
@@ -49,10 +45,10 @@ final class Future
      * Note: If task is running, it will be interrupted.
      * Warning: Internal function calls in progress cannot be interrupted.
      *
+     * @return bool
+     *
      * @throws Future\Error\Killed if \parallel\Runtime executing task was killed.
      * @throws Future\Error\Cancelled if task was already cancelled.
      */
-    public function cancel(): bool
-    {
-    }
+    public function cancel(): bool {}
 }