diff --git a/calendar/inc/class.calendar_ical.inc.php b/calendar/inc/class.calendar_ical.inc.php
index 5635a700c9..7e7e5a32a6 100644
--- a/calendar/inc/class.calendar_ical.inc.php
+++ b/calendar/inc/class.calendar_ical.inc.php
@@ -1799,11 +1799,14 @@ class calendar_ical extends calendar_boupdate
 				{
 					case 'G':
 					case 'P':
+					case 0:
 						$owner = $this->user;
-				}
-				if (0 < (int)$owner && $this->check_perms(EGW_ACL_EDIT, 0, $owner))
-				{
-					$this->calendarOwner = $owner;
+						break;
+					default:
+						if ((int)$owner && $this->check_perms(EGW_ACL_EDIT, 0, $owner))
+						{
+							$this->calendarOwner = $owner;
+						}
 				}
 			}
 			if (!isset($this->productManufacturer) ||
diff --git a/calendar/inc/class.calendar_sif.inc.php b/calendar/inc/class.calendar_sif.inc.php
index 2888f16fee..46795063ed 100644
--- a/calendar/inc/class.calendar_sif.inc.php
+++ b/calendar/inc/class.calendar_sif.inc.php
@@ -1217,11 +1217,14 @@ class calendar_sif extends calendar_boupdate
 				{
 					case 'G':
 					case 'P':
+					case 0:
 						$owner = $this->user;
-				}
-				if (0 < (int)$owner && $this->check_perms(EGW_ACL_EDIT, 0, $owner))
-				{
-					$this->calendarOwner = $owner;
+						break;
+					default:
+						if ((int)$owner && $this->check_perms(EGW_ACL_EDIT, 0, $owner))
+						{
+							$this->calendarOwner = $owner;
+						}
 				}
 			}
 		}