diff --git a/src/calibre/ebooks/oeb/base.py b/src/calibre/ebooks/oeb/base.py
index cf80e4abe2..632696b4ae 100644
--- a/src/calibre/ebooks/oeb/base.py
+++ b/src/calibre/ebooks/oeb/base.py
@@ -25,6 +25,7 @@ from calibre.translations.dynamic import translate
 from calibre.ebooks.chardet import xml_to_unicode
 from calibre.ebooks.oeb.entitydefs import ENTITYDEFS
 from calibre.ebooks.conversion.preprocess import CSSPreProcessor
+from calibre import isbytestring
 
 RECOVER_PARSER = etree.XMLParser(recover=True, no_network=True)
 
@@ -404,7 +405,8 @@ class DirContainer(object):
 
     def __init__(self, path, log):
         self.log = log
-        path = unicode(path)
+        if isbytestring(path):
+            path = path.decode(filesystem_encoding)
         ext = os.path.splitext(path)[1].lower()
         if ext == '.opf':
             self.opfname = os.path.basename(path)
diff --git a/src/calibre/ptempfile.py b/src/calibre/ptempfile.py
index 0aa71770a0..71ae9b0789 100644
--- a/src/calibre/ptempfile.py
+++ b/src/calibre/ptempfile.py
@@ -7,8 +7,7 @@ being closed.
 """
 import tempfile, os, atexit, binascii, cPickle
 
-from calibre import __version__, __appname__, isbytestring
-from calibre.constants import filesystem_encoding
+from calibre.constants import __version__, __appname__
 
 def cleanup(path):
     try:
@@ -43,8 +42,6 @@ def base_dir():
             _base_dir = tempfile.mkdtemp(prefix='%s_%s_tmp_'%(__appname__,
                 __version__))
             atexit.register(remove_dir, _base_dir)
-    if isbytestring(_base_dir):
-        _base_dir = _base_dir.decode(filesystem_encoding)
     return _base_dir
 
 class PersistentTemporaryFile(object):