diff --git a/calendar/inc/class.calendar_bo.inc.php b/calendar/inc/class.calendar_bo.inc.php
index fe645e0550..ecea774d78 100644
--- a/calendar/inc/class.calendar_bo.inc.php
+++ b/calendar/inc/class.calendar_bo.inc.php
@@ -1067,8 +1067,8 @@ class calendar_bo
 		}
 		$grants = $this->grants[$owner];
 
-		// now any ACL rights implicate FREEBUSY rights (at least READ has to include FREEBUSY)
-		if ($grants) $grants |= EGW_ACL_FREEBUSY;
+		// now any ACL rights (but invite rights!) implicate FREEBUSY rights (at least READ has to include FREEBUSY)
+		if ($grants & ~EGW_ACL_INVITE) $grants |= EGW_ACL_FREEBUSY;
 
 		if (is_array($event) && ($needed == EGW_ACL_READ || $needed == EGW_ACL_FREEBUSY))
 		{