diff --git a/src/Symfony/Component/Mime/Part/DataPart.php b/src/Symfony/Component/Mime/Part/DataPart.php
index b42ecb4da102e..c5ca9410db224 100644
--- a/src/Symfony/Component/Mime/Part/DataPart.php
+++ b/src/Symfony/Component/Mime/Part/DataPart.php
@@ -26,10 +26,12 @@ class DataPart extends TextPart
     private $mediaType;
     private $cid;
 
+    private $formEncoding;
+
     /**
      * @param resource|string|File $body Use a File instance to defer loading the file until rendering
      */
-    public function __construct($body, string $filename = null, string $contentType = null, string $encoding = null)
+    public function __construct($body, string $filename = null, string $contentType = null, string $encoding = null, string $formEncoding = null)
     {
         unset($this->_parent);
 
@@ -42,6 +44,8 @@ public function __construct($body, string $filename = null, string $contentType
 
         parent::__construct($body, null, $subtype, $encoding);
 
+        $this->formEncoding = $formEncoding ?? '8bit';
+
         if (null !== $filename) {
             $this->filename = $filename;
             $this->setName($filename);
@@ -49,9 +53,9 @@ public function __construct($body, string $filename = null, string $contentType
         $this->setDisposition('attachment');
     }
 
-    public static function fromPath(string $path, string $name = null, string $contentType = null): self
+    public static function fromPath(string $path, string $name = null, string $contentType = null, string $encoding = null): self
     {
-        return new self(new File($path), $name, $contentType);
+        return new self(new File($path), $name, $contentType, $encoding, $encoding);
     }
 
     /**
diff --git a/src/Symfony/Component/Mime/Part/Multipart/FormDataPart.php b/src/Symfony/Component/Mime/Part/Multipart/FormDataPart.php
index 54a7c76a353a0..a0484b17cfc9a 100644
--- a/src/Symfony/Component/Mime/Part/Multipart/FormDataPart.php
+++ b/src/Symfony/Component/Mime/Part/Multipart/FormDataPart.php
@@ -94,16 +94,35 @@ private function preparePart(string $name, string|TextPart $value): TextPart
 
     private function configurePart(string $name, TextPart $part): TextPart
     {
-        static $r;
-
-        $r ??= new \ReflectionProperty(TextPart::class, 'encoding');
-
         $part->setDisposition('form-data');
         $part->setName($name);
         // HTTP does not support \r\n in header values
         $part->getHeaders()->setMaxLineLength(\PHP_INT_MAX);
-        $r->setValue($part, '8bit');
+        if ($part instanceof DataPart) {
+            // data part may specify base64 encoding
+            $this->configureDataPartEncoding($part);
+        } else {
+            $this->configureTextPartEncoding($part);
+        }
 
         return $part;
     }
+
+    private function configureDataPartEncoding(DataPart $part)
+    {
+        static $r;
+
+        $r ??= new \ReflectionProperty(DataPart::class, 'formEncoding');
+        $formEncoding = $r->getValue($part);
+
+        $this->configureTextPartEncoding($part, $formEncoding);
+    }
+
+    private function configureTextPartEncoding(TextPart $part, $encoding = '8bit')
+    {
+        static $r;
+
+        $r ??= new \ReflectionProperty(TextPart::class, 'encoding');
+        $r->setValue($part, $encoding);
+    }
 }
diff --git a/src/Symfony/Component/Mime/Tests/EmailTest.php b/src/Symfony/Component/Mime/Tests/EmailTest.php
index c4f829d7d12de..c47fe23ec5606 100644
--- a/src/Symfony/Component/Mime/Tests/EmailTest.php
+++ b/src/Symfony/Component/Mime/Tests/EmailTest.php
@@ -530,6 +530,7 @@ public function testSymfonySerialize()
         {
             "filename": "test.txt",
             "mediaType": "application",
+            "formEncoding": "8bit",
             "body": "Some Text file",
             "charset": null,
             "subtype": "octet-stream",
diff --git a/src/Symfony/Component/Mime/Tests/Part/Multipart/FormDataPartTest.php b/src/Symfony/Component/Mime/Tests/Part/Multipart/FormDataPartTest.php
index 7ac3336f90666..e78b1d6a6597b 100644
--- a/src/Symfony/Component/Mime/Tests/Part/Multipart/FormDataPartTest.php
+++ b/src/Symfony/Component/Mime/Tests/Part/Multipart/FormDataPartTest.php
@@ -47,6 +47,27 @@ public function testConstructor()
         $this->assertEquals([$t, $b, $c], $f->getParts());
     }
 
+    public function testConstructorWithBase64Encoding()
+    {
+        $r = new \ReflectionProperty(TextPart::class, 'encoding');
+
+        $d = DataPart::fromPath($file = __DIR__.'/../../Fixtures/mimetypes/test.gif', null, null, '8bit');
+        $e = DataPart::fromPath($file = __DIR__.'/../../Fixtures/mimetypes/test.gif', null, null, 'base64');
+        $f = new FormDataPart([
+            'foo' => clone $d,
+            'bar' => clone $e
+        ]);
+        $d->setDisposition('form-data');
+        $d->setName('foo');
+        $d->getHeaders()->setMaxLineLength(\PHP_INT_MAX);
+        $r->setValue($d, '8bit');
+        $e->setDisposition('form-data');
+        $e->setName('bar');
+        $e->getHeaders()->setMaxLineLength(\PHP_INT_MAX);
+        $r->setValue($e, 'base64');
+        $this->assertEquals([$d, $e], $f->getParts());
+    }
+
     public function testNestedArrayParts()
     {
         $p1 = new TextPart('content', 'utf-8', 'plain', '8bit');