diff --git a/snappymail/v/0.0.0/app/libraries/snappymail/image.php b/snappymail/v/0.0.0/app/libraries/snappymail/image.php
index 2f412b209..2469de1df 100644
--- a/snappymail/v/0.0.0/app/libraries/snappymail/image.php
+++ b/snappymail/v/0.0.0/app/libraries/snappymail/image.php
@@ -4,7 +4,7 @@ namespace SnappyMail;
 
 interface Image
 {
-	public static function createFromString(string $data);
+	public static function createFromString(string &$data);
 
 	public function getOrientation() : int;
 
diff --git a/snappymail/v/0.0.0/app/libraries/snappymail/image/gd2.php b/snappymail/v/0.0.0/app/libraries/snappymail/image/gd2.php
index 3d8d3d10a..ef5a027e3 100644
--- a/snappymail/v/0.0.0/app/libraries/snappymail/image/gd2.php
+++ b/snappymail/v/0.0.0/app/libraries/snappymail/image/gd2.php
@@ -29,7 +29,7 @@ class GD2 implements \SnappyMail\Image
 		return $this->getImageBlob();
 	}
 
-	public static function createFromString(string $data)
+	public static function createFromString(string &$data)
 	{
 		if (!($imginfo = \getimagesizefromstring($data))) {
 			throw new \InvalidArgumentException('Invalid image');
diff --git a/snappymail/v/0.0.0/app/libraries/snappymail/image/gmagick.php b/snappymail/v/0.0.0/app/libraries/snappymail/image/gmagick.php
index a5ec141ba..38480d586 100644
--- a/snappymail/v/0.0.0/app/libraries/snappymail/image/gmagick.php
+++ b/snappymail/v/0.0.0/app/libraries/snappymail/image/gmagick.php
@@ -14,7 +14,7 @@ class GMagick extends \Gmagick implements \SnappyMail\Image
 		$this->clear();
 	}
 
-	public static function createFromString(string $data)
+	public static function createFromString(string &$data)
 	{
 		$gmagick = new static();
 		if (!$gmagick->readimageblob($data)) {
diff --git a/snappymail/v/0.0.0/app/libraries/snappymail/image/imagick.php b/snappymail/v/0.0.0/app/libraries/snappymail/image/imagick.php
index 2cc75ddab..8c67e6483 100644
--- a/snappymail/v/0.0.0/app/libraries/snappymail/image/imagick.php
+++ b/snappymail/v/0.0.0/app/libraries/snappymail/image/imagick.php
@@ -11,7 +11,7 @@ class IMagick extends \Imagick implements \SnappyMail\Image
 		$this->clear();
 	}
 
-	public static function createFromString(string $data)
+	public static function createFromString(string &$data)
 	{
 		$imagick = new static();
 		if (!$imagick->readImageBlob($data)) {