diff --git a/src/Fgits/CarbonGermanHolidays/CarbonGermanHolidays.php b/src/Fgits/CarbonGermanHolidays/CarbonGermanHolidays.php
index a499df7..1986e06 100644
--- a/src/Fgits/CarbonGermanHolidays/CarbonGermanHolidays.php
+++ b/src/Fgits/CarbonGermanHolidays/CarbonGermanHolidays.php
@@ -140,7 +140,7 @@ public static function getHolidays($year, $states = self::ALL_STATES)
             $states = array($states);
         }
 
-        $penanceDay = mktime(0, 0, 0, 11, 22 - ($year - 1 + $year / 4) % 7, $year);
+        $penanceDay = mktime(0, 0, 0, 11, 22 - ($year - 1 + ((int) ((int) ($year / 4)) % 7)), $year);
 
 
         // For all states