diff --git a/lib/Doctrine/Common/Proxy/ProxyGenerator.php b/lib/Doctrine/Common/Proxy/ProxyGenerator.php
index 1401bcbf7..0714d3884 100644
--- a/lib/Doctrine/Common/Proxy/ProxyGenerator.php
+++ b/lib/Doctrine/Common/Proxy/ProxyGenerator.php
@@ -1091,10 +1091,7 @@ private function buildParametersString(array $parameters, array $renameParameter
             }
 
             $parameterDefinition .= '$' . ($renameParameters ? $renameParameters[$i] : $param->getName());
-
-            if ($param->isDefaultValueAvailable()) {
-                $parameterDefinition .= ' = ' . var_export($param->getDefaultValue(), true);
-            }
+            $parameterDefinition .= $this->getParameterDefaultValue($param);
 
             $parameterDefinitions[] = $parameterDefinition;
         }
@@ -1118,6 +1115,24 @@ private function getParameterType(ReflectionParameter $parameter)
         return $this->formatType($parameter->getType(), $declaringFunction, $parameter);
     }
 
+    /**
+     * @return string
+     */
+    private function getParameterDefaultValue(ReflectionParameter $parameter)
+    {
+        if (! $parameter->isDefaultValueAvailable()) {
+            return '';
+        }
+
+        if (PHP_VERSION_ID < 80100) {
+            return ' = ' . var_export($parameter->getDefaultValue(), true);
+        }
+
+        $value = rtrim(substr(explode('$' . $parameter->getName() . ' = ', (string) $parameter, 2)[1], 0, -2));
+
+        return ' = ' . $value;
+    }
+
     /**
      * @param ReflectionParameter[] $parameters
      *
diff --git a/tests/Doctrine/Tests/Common/Proxy/PHP81NewInInitializers.php b/tests/Doctrine/Tests/Common/Proxy/PHP81NewInInitializers.php
new file mode 100644
index 000000000..d9c40da87
--- /dev/null
+++ b/tests/Doctrine/Tests/Common/Proxy/PHP81NewInInitializers.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Common\Proxy;
+
+class PHP81NewInInitializers
+{
+    public function onlyInitializer($foo = new \stdClass()): void
+    {
+
+    }
+
+    public function typed(\DateTimeInterface $foo = new \DateTimeImmutable('now')): void
+    {
+
+    }
+
+    public function arrayInDefault(array $foo = [new \DateTimeImmutable('2022-08-22 16:20', new \DateTimeZone('Europe/Warsaw'))]): void
+    {
+
+    }
+}
diff --git a/tests/Doctrine/Tests/Common/Proxy/ProxyGeneratorTest.php b/tests/Doctrine/Tests/Common/Proxy/ProxyGeneratorTest.php
index e03f8d717..dde498847 100644
--- a/tests/Doctrine/Tests/Common/Proxy/ProxyGeneratorTest.php
+++ b/tests/Doctrine/Tests/Common/Proxy/ProxyGeneratorTest.php
@@ -572,6 +572,36 @@ public function testEnumDefaultInPublicProperty() : void
         $this->assertSame($object->isEnum, \Doctrine\Tests\Common\Proxy\YesOrNo::YES);
     }
 
+    /**
+     * @requires PHP >= 8.1.0
+     */
+    public function testPhp81NewInInitializers()
+    {
+        $className = PHP81NewInInitializers::class;
+
+        if (!class_exists('Doctrine\Tests\Common\ProxyProxy\__CG__\PHP81NewInInitializers', false)) {
+            $metadata = $this->createClassMetadata($className, ['id']);
+
+            $proxyGenerator = new ProxyGenerator(__DIR__ . '/generated', __NAMESPACE__ . 'Proxy');
+            $this->generateAndRequire($proxyGenerator, $metadata);
+        }
+
+        self::assertStringContainsString(
+            'onlyInitializer($foo = new \stdClass()): void',
+            file_get_contents(__DIR__ . '/generated/__CG__DoctrineTestsCommonProxyPHP81NewInInitializers.php')
+        );
+
+        self::assertStringContainsString(
+            'typed(\DateTimeInterface $foo = new \DateTimeImmutable(\'now\')): void',
+            file_get_contents(__DIR__ . '/generated/__CG__DoctrineTestsCommonProxyPHP81NewInInitializers.php')
+        );
+
+        self::assertStringContainsString(
+            'arrayInDefault(array $foo = [new \DateTimeImmutable(\'2022-08-22 16:20\', new \DateTimeZone(\'Europe/Warsaw\'))]): void',
+            file_get_contents(__DIR__ . '/generated/__CG__DoctrineTestsCommonProxyPHP81NewInInitializers.php')
+        );
+    }
+
     /**
      * @param string  $className
      * @param mixed[] $ids