diff --git a/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php b/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
index 07c3d49db05d..900cbaad0a29 100644
--- a/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
+++ b/src/Symfony/Component/ErrorHandler/Exception/FlattenException.php
@@ -206,7 +206,7 @@ public function setMessage($message): self
         return $this;
     }
 
-    public function getCode(): int
+    public function getCode()
     {
         return $this->code;
     }
diff --git a/src/Symfony/Component/ErrorHandler/Tests/Exception/FlattenExceptionTest.php b/src/Symfony/Component/ErrorHandler/Tests/Exception/FlattenExceptionTest.php
index 66212a81ad84..437d211f7159 100644
--- a/src/Symfony/Component/ErrorHandler/Tests/Exception/FlattenExceptionTest.php
+++ b/src/Symfony/Component/ErrorHandler/Tests/Exception/FlattenExceptionTest.php
@@ -14,6 +14,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Debug\Exception\FatalThrowableError;
 use Symfony\Component\ErrorHandler\Exception\FlattenException;
+use Symfony\Component\ErrorHandler\Tests\Fixtures\StringErrorCodeException;
 use Symfony\Component\HttpFoundation\Exception\SuspiciousOperationException;
 use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
@@ -197,6 +198,15 @@ public function testFile(\Throwable $exception)
         $this->assertSame($exception->getFile(), $flattened->getFile());
     }
 
+    /**
+     * @dataProvider stringAndIntDataProvider
+     */
+    public function testCode(\Throwable $exception)
+    {
+        $flattened = FlattenException::createFromThrowable($exception);
+        $this->assertSame($exception->getCode(), $flattened->getCode());
+    }
+
     /**
      * @dataProvider flattenDataProvider
      */
@@ -238,6 +248,14 @@ public function flattenDataProvider(): array
         ];
     }
 
+    public function stringAndIntDataProvider(): array
+    {
+        return [
+            [new \Exception('test1', 123)],
+            [new StringErrorCodeException('test2', '42S02')],
+        ];
+    }
+
     public function testArguments()
     {
         if (\PHP_VERSION_ID >= 70400) {
diff --git a/src/Symfony/Component/ErrorHandler/Tests/Fixtures/StringErrorCodeException.php b/src/Symfony/Component/ErrorHandler/Tests/Fixtures/StringErrorCodeException.php
new file mode 100644
index 000000000000..d4cbc02abe9b
--- /dev/null
+++ b/src/Symfony/Component/ErrorHandler/Tests/Fixtures/StringErrorCodeException.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Symfony\Component\ErrorHandler\Tests\Fixtures;
+
+class StringErrorCodeException extends \Exception
+{
+
+    public function __construct(string $message, string $code) {
+        parent::__construct($message);
+        $this->code = $code;
+    }
+
+}