diff --git a/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php b/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
--- a/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
+++ b/src/applications/calendar/editor/PhabricatorCalendarEventEditor.php
@@ -34,25 +34,22 @@
     }
 
     $actor = $this->getActor();
+
+    $invitees = $event->getInvitees();
+
     $event->copyFromParent($actor);
     $event->setIsStub(0);
 
-    $invitees = $event->getParentEvent()->getInvitees();
-
-    $new_invitees = array();
-    foreach ($invitees as $invitee) {
-      $invitee = id(new PhabricatorCalendarEventInvitee())
-        ->setEventPHID($event->getPHID())
-        ->setInviteePHID($invitee->getInviteePHID())
-        ->setInviterPHID($invitee->getInviterPHID())
-        ->setStatus($invitee->getStatus())
-        ->save();
-
-      $new_invitees[] = $invitee;
-    }
+    $event->openTransaction();
+      $event->save();
+      foreach ($invitees as $invitee) {
+        $invitee
+          ->setEventPHID($event->getPHID())
+          ->save();
+      }
+    $event->saveTransaction();
 
-    $event->save();
-    $event->attachInvitees($new_invitees);
+    $event->attachInvitees($invitees);
   }
 
   public function getTransactionTypes() {
diff --git a/src/applications/calendar/storage/PhabricatorCalendarEvent.php b/src/applications/calendar/storage/PhabricatorCalendarEvent.php
--- a/src/applications/calendar/storage/PhabricatorCalendarEvent.php
+++ b/src/applications/calendar/storage/PhabricatorCalendarEvent.php
@@ -27,7 +27,6 @@
 
   protected $isRecurring = 0;
 
-  private $isGhostEvent = false;
   protected $instanceOfEventPHID;
   protected $sequenceIndex;
 
@@ -60,6 +59,9 @@
   protected $recurrenceEndDate;
   protected $recurrenceFrequency = array();
 
+  private $isGhostEvent = false;
+  private $stubInvitees;
+
   public static function initializeNewCalendarEvent(PhabricatorUser $actor) {
     $app = id(new PhabricatorApplicationQuery())
       ->setViewer($actor)
@@ -449,9 +451,34 @@
   }
 
   public function getInvitees() {
+    if ($this->getIsGhostEvent() || $this->getIsStub()) {
+      if ($this->stubInvitees === null) {
+        $this->stubInvitees = $this->newStubInvitees();
+      }
+      return $this->stubInvitees;
+    }
+
     return $this->assertAttached($this->invitees);
   }
 
+  private function newStubInvitees() {
+    $parent = $this->getParentEvent();
+
+    $parent_invitees = $parent->getInvitees();
+    $stub_invitees = array();
+
+    foreach ($parent_invitees as $invitee) {
+      $stub_invitee = id(new PhabricatorCalendarEventInvitee())
+        ->setInviteePHID($invitee->getInviteePHID())
+        ->setInviterPHID($invitee->getInviterPHID())
+        ->setStatus(PhabricatorCalendarEventInvitee::STATUS_INVITED);
+
+      $stub_invitees[] = $stub_invitee;
+    }
+
+    return $stub_invitees;
+  }
+
   public function attachInvitees(array $invitees) {
     $this->invitees = $invitees;
     return $this;
@@ -478,6 +505,7 @@
     if (!$invited) {
       return PhabricatorCalendarEventInvitee::STATUS_UNINVITED;
     }
+
     $invited = $invited->getStatus();
     return $invited;
   }