diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
index 3306377898..c3b4bcb0fc 100644
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -1205,8 +1205,8 @@ abstract class PhabricatorApplicationTransactionEditor
     PhabricatorLiskDAO $object,
     array $xactions) {
 
-    $email_to = array_unique($this->getMailTo($object));
-    $email_cc = array_unique($this->getMailCC($object));
+    $email_to = array_filter(array_unique($this->getMailTo($object)));
+    $email_cc = array_filter(array_unique($this->getMailCC($object)));
 
     $phids = array_merge($email_to, $email_cc);
     $handles = id(new PhabricatorHandleQuery())