diff --git a/src/Util/Images.php b/src/Util/Images.php
index f468e69c2d..05b3573dd2 100644
--- a/src/Util/Images.php
+++ b/src/Util/Images.php
@@ -343,7 +343,8 @@ class Images
 	 * @param string $preview Preview image URL
 	 * @param string $description
 	 * @return string
-	 */	public static function getBBCodeByUrl(string $photo, string $preview = null, string $description = null): string
+	 */
+	public static function getBBCodeByUrl(string $photo, string $preview = null, string $description = ''): string
 	{
 		if (!empty($preview)) {
 			return '[url=' . $photo . '][img=' . $preview . ']' . $description . '[/img][/url]';