diff --git a/CHANGELOG.md b/CHANGELOG.md
index a8cceb1..a62b3d3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## 1.1.1
 
 * fix: Fix missing `kernel.reset` tags.
+* fix: Proxy generation under `opcache` and/or `classmap-authoritative`
 
 ## 1.1.0
 
diff --git a/composer.json b/composer.json
index fffa948..11a972c 100644
--- a/composer.json
+++ b/composer.json
@@ -36,6 +36,7 @@
         "symfony/property-access": "^6.4 || ^7.0",
         "symfony/property-info": "^6.4 || ^7.0",
         "symfony/serializer": "^6.4 || ^7.0",
+        "symfony/service-contracts": "^3.0",
         "symfony/var-exporter": "^6.4.1 || ^6.5 || ^7.0.1 || ^7.1"
     },
     "require-dev": {
diff --git a/src/Proxy/Implementation/ProxyFactory.php b/src/Proxy/Implementation/ProxyFactory.php
index 6b0add3..2d7db93 100644
--- a/src/Proxy/Implementation/ProxyFactory.php
+++ b/src/Proxy/Implementation/ProxyFactory.php
@@ -44,11 +44,15 @@ public function createProxy(
     ): object {
         $targetProxyClass = ProxyNamer::generateProxyClassName($class);
 
-        if (!class_exists($targetProxyClass, false)) {
+        if (!class_exists($targetProxyClass)) {
             $sourceCode = $this->proxyGenerator
                 ->generateProxyCode($class, $targetProxyClass);
             $this->proxyRegistry->registerProxy($targetProxyClass, $sourceCode);
 
+            // @phpstan-ignore-next-line
+            eval($sourceCode);
+
+            // @phpstan-ignore-next-line
             if (!class_exists($targetProxyClass)) {
                 throw new LogicException(
                     sprintf('Unable to find target proxy class "%s".', $targetProxyClass),
diff --git a/src/Proxy/Implementation/ProxyGenerator.php b/src/Proxy/Implementation/ProxyGenerator.php
index d153974..66735ec 100644
--- a/src/Proxy/Implementation/ProxyGenerator.php
+++ b/src/Proxy/Implementation/ProxyGenerator.php
@@ -53,7 +53,7 @@ private function generateProxySourceCode(string $realClass, string $proxyClass):
             sprintf('namespace %s;', $namespace) . "\n\n" .
             sprintf(
                 'final %sclass %s%s',
-                $targetReflection->isReadOnly() ? 'readonly ' : ' ',
+                $targetReflection->isReadOnly() ? 'readonly ' : '',
                 $shortName,
                 ProxyHelper::generateLazyGhost($targetReflection)
             );
@@ -62,10 +62,6 @@ private function generateProxySourceCode(string $realClass, string $proxyClass):
     private function getClassHeader(): string
     {
         return <<<'PHP'
-<?php
-
-declare(strict_types=1);
-
 /*
  * This is a proxy class automatically generated by the rekalogika/mapper
  * package. Do not edit it manually.
diff --git a/src/Proxy/Implementation/ProxyRegistry.php b/src/Proxy/Implementation/ProxyRegistry.php
index 20a8ecf..5d7b200 100644
--- a/src/Proxy/Implementation/ProxyRegistry.php
+++ b/src/Proxy/Implementation/ProxyRegistry.php
@@ -41,6 +41,11 @@ public function registerProxy(string $class, string $sourceCode): void
             self::getProxyFileName($class)
         );
 
+        $sourceCode = sprintf(
+            '<?php declare(strict_types=1);' . "\n\n" . '%s',
+            $sourceCode
+        );
+
         file_put_contents($proxyFile, $sourceCode);
     }