diff --git a/lib/Horde/ActiveSync/Imap/Message.php b/lib/Horde/ActiveSync/Imap/Message.php
index d0647e48..babbbb7e 100644
--- a/lib/Horde/ActiveSync/Imap/Message.php
+++ b/lib/Horde/ActiveSync/Imap/Message.php
@@ -500,7 +500,8 @@ public function getMimePart($id, array $options = [])
     {
         $part = $this->basePart->getPart($id);
         if ($part
-            && (strcasecmp($part->getCharset(), 'ISO-8859-1') === 0)) {
+            && $part->getCharset()
+            && strcasecmp($part->getCharset(), 'ISO-8859-1') === 0) {
             $part->setCharset('windows-1252');
         }