diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Utils.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Utils.php
index 3f36ed9c8..25075cfbe 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Utils.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Utils.php
@@ -55,12 +55,12 @@ class Utils
 		);
 	}
 
-	public static function DecodeKeyValuesQ(string $sEncodedValues, string $sCustomKey = '') : array
+	public static function DecodeKeyValuesQ(string $sEncodedValues, string $sCustomKey = '') : ?array
 	{
 		return \SnappyMail\Crypt::DecryptUrlSafe(
 			$sEncodedValues,
 			\sha1(APP_SALT.$sCustomKey.'Q'.static::GetSessionToken())
-		);
+		) ?: null;
 	}
 
 	public static function unserialize(string $sDecodedValues) : array