diff --git a/api/src/Mail/Html.php b/api/src/Mail/Html.php
index 667b845e4f..470e871ae6 100644
--- a/api/src/Mail/Html.php
+++ b/api/src/Mail/Html.php
@@ -555,7 +555,7 @@ class Html
 			$searchFor = '<pre>';
 			$pos = stripos($html,$searchFor);
 		}
-		if ($pos === false)
+		if ($pos === false || !$html)
 		{
 			return $html;
 		}