diff --git a/src/applications/people/mail/PhabricatorPeopleWelcomeMailEngine.php b/src/applications/people/mail/PhabricatorPeopleWelcomeMailEngine.php
--- a/src/applications/people/mail/PhabricatorPeopleWelcomeMailEngine.php
+++ b/src/applications/people/mail/PhabricatorPeopleWelcomeMailEngine.php
@@ -118,14 +118,14 @@
     $recipient = $this->getRecipient();
 
     $custom_body = $this->getWelcomeMessage();
-    if (strlen($custom_body)) {
+    if (phutil_nonempty_string($custom_body)) {
       return $this->newRemarkupText($custom_body);
     }
 
     $default_body = PhabricatorAuthMessage::loadMessageText(
       $recipient,
       PhabricatorAuthWelcomeMailMessageType::MESSAGEKEY);
-    if (strlen($default_body)) {
+    if (phutil_nonempty_string($default_body)) {
       return $this->newRemarkupText($default_body);
     }