diff --git a/src/Promise/Declaration/Extractor/Methods.php b/src/Promise/Declaration/Extractor/Methods.php
index 46cde4b..80e8e4e 100644
--- a/src/Promise/Declaration/Extractor/Methods.php
+++ b/src/Promise/Declaration/Extractor/Methods.php
@@ -60,6 +60,7 @@ public function __construct(
     /**
      * @param \ReflectionClass $reflection
      * @return array
+     * @throws \ReflectionException
      */
     public function getMethods(\ReflectionClass $reflection): array
     {
@@ -198,6 +199,14 @@ private function packParams(\ReflectionMethod $method): array
                 $param->setDefault($parameter->getDefaultValue());
             }
 
+            if ($parameter->isVariadic()) {
+                $param->makeVariadic();
+            }
+
+            if ($parameter->isPassedByReference()) {
+                $param->makeByRef();
+            }
+
             $type = $this->defineParamReturnType($parameter);
             if ($type !== null) {
                 $param->setType($type);
diff --git a/tests/Promise/ProxyPrinter/Methods/Fixtures/ArgsFixture.php b/tests/Promise/ProxyPrinter/Methods/Fixtures/ArgsFixture.php
index f264415..2b2996f 100644
--- a/tests/Promise/ProxyPrinter/Methods/Fixtures/ArgsFixture.php
+++ b/tests/Promise/ProxyPrinter/Methods/Fixtures/ArgsFixture.php
@@ -7,6 +7,10 @@
 
 class ArgsFixture
 {
+    public function referencedSetter(string $a, &$b, int $c): void
+    {
+    }
+
     public function typedSetter(string $a, $b, int $c): void
     {
     }
@@ -15,4 +19,8 @@ public function typedSetter(string $a, $b, int $c): void
     public function defaultsSetter(string $a, $b = [], int $c = 3, bool $d): void
     {
     }
+
+    public function variadicSetter($a, string ...$b): void
+    {
+    }
 }
diff --git a/tests/Promise/ProxyPrinter/Methods/MethodArgsTest.php b/tests/Promise/ProxyPrinter/Methods/MethodArgsTest.php
index d8c24fe..a103356 100644
--- a/tests/Promise/ProxyPrinter/Methods/MethodArgsTest.php
+++ b/tests/Promise/ProxyPrinter/Methods/MethodArgsTest.php
@@ -14,30 +14,50 @@ class MethodArgsTest extends BaseProxyPrinterTest
      */
     public function testHasArgType(): void
     {
-        $classname = Fixtures\ArgsFixture::class;
-        $as = self::NS . __CLASS__ . __LINE__;
-        $reflection = new \ReflectionClass($classname);
+        $output = $this->makeOutput(Fixtures\ArgsFixture::class, self::NS . __CLASS__ . __LINE__);
 
-        $parent = Declarations::createParentFromReflection($reflection);
-        $class = Declarations::createClassFromName($as, $parent);
+        $this->assertStringContainsString('typedSetter(string $a, $b, int $c)', $output);
+    }
 
-        $output = $this->make($reflection, $class, $parent);
-        $output = ltrim($output, '<?php');
+    /**
+     * @throws \ReflectionException
+     */
+    public function testArgDefaults(): void
+    {
+        $output = $this->makeOutput(Fixtures\ArgsFixture::class, self::NS . __CLASS__ . __LINE__);
 
-        $this->assertFalse(class_exists($class->getFullName()));
+        //Long syntax by default
+        $this->assertStringContainsString('defaultsSetter(string $a, $b = array(), int $c = 3, bool $d)', $output);
+    }
 
-        eval($output);
+    /**
+     * @throws \ReflectionException
+     */
+    public function testVariadicArg(): void
+    {
+        $output = $this->makeOutput(Fixtures\ArgsFixture::class, self::NS . __CLASS__ . __LINE__);
 
-        $this->assertStringContainsString('typedSetter(string $a, $b, int $c)', $output);
+        $this->assertStringContainsString('public function variadicSetter($a, string ...$b)', $output);
     }
 
     /**
      * @throws \ReflectionException
      */
-    public function testArgDefaults(): void
+    public function testReferencedArg(): void
+    {
+        $output = $this->makeOutput(Fixtures\ArgsFixture::class, self::NS . __CLASS__ . __LINE__);
+
+        $this->assertStringContainsString('public function referencedSetter(string $a, &$b, int $c)', $output);
+    }
+
+    /**
+     * @param string $classname
+     * @param string $as
+     * @return string
+     * @throws \ReflectionException
+     */
+    private function makeOutput(string $classname, string $as): string
     {
-        $classname = Fixtures\ArgsFixture::class;
-        $as = self::NS . __CLASS__ . __LINE__;
         $reflection = new \ReflectionClass($classname);
 
         $parent = Declarations::createParentFromReflection($reflection);
@@ -50,12 +70,6 @@ public function testArgDefaults(): void
 
         eval($output);
 
-        //Long syntax by default
-        $this->assertStringContainsString('defaultsSetter(string $a, $b = array(), int $c = 3, bool $d)', $output);
-    }
-
-    public function testArgVariadic(): void
-    {
-        $this->assertTrue(true);
+        return $output;
     }
 }