diff --git a/inc/Service/Media/FallbackMediaHandler.php b/inc/Service/Media/FallbackMediaHandler.php
index 9003dae7..66203f01 100644
--- a/inc/Service/Media/FallbackMediaHandler.php
+++ b/inc/Service/Media/FallbackMediaHandler.php
@@ -12,12 +12,27 @@ class FallbackMediaHandler implements MediaHandler {
 	private string $mime;
 
 
-	public function __construct(ImageMetadataReader $image_metadate_reader, string $default_thumb_path) {
-		$res = $image_metadate_reader->getMetadata($default_thumb_path);
+	private static function getShape(string $file_path) {
+		$ret = \getimagesize($file_path);
+		if ($ret === false) {
+			throw new \RuntimeException("Could not read image sizes of '$file_path'");
+		}
+		if ($ret[2] == \IMAGETYPE_UNKNOWN) {
+			throw new \RuntimeException("Error '$file_path' is not an image");
+		}
+
+		$width = $ret[0];
+		$height = $ret[1];
+		$mime = $ret['mime'];
+		return [ $width, $height, $mime ];
+	}
+
+	public function __construct(string $default_thumb_path) {
+		list($width, $height, $mime) = self::getShape($default_thumb_path);
 		$this->path = $default_thumb_path;
-		$this->width = $res->width;
-		$this->height = $res->height;
-		$this->mime = $res->mime;
+		$this->width = $width;
+		$this->height = $height;
+		$this->mime = $mime;
 	}
 
 	public function supportsMime(string $mime): bool {