diff --git a/src/calibre/ebooks/pdf/render/common.py b/src/calibre/ebooks/pdf/render/common.py
index f00e13639f..b351ce5c08 100644
--- a/src/calibre/ebooks/pdf/render/common.py
+++ b/src/calibre/ebooks/pdf/render/common.py
@@ -128,8 +128,7 @@ class String(unicode):
 class UTF16String(unicode):
 
     def pdf_serialize(self, stream):
-        s = self.replace('\\', '\\\\')
-        raw = codecs.BOM_UTF16_BE + s.encode('utf-16-be')
+        raw = codecs.BOM_UTF16_BE + self.encode('utf-16-be').replace(b'\\', b'\\\\')
         stream.write(b'('+escape_unbalanced_parantheses(raw)+b')')
 
 class Dictionary(dict):