diff --git a/src/calibre/gui2/viewer/convert_book.py b/src/calibre/gui2/viewer/convert_book.py
index 52c10fb38c..3f1e1e3850 100644
--- a/src/calibre/gui2/viewer/convert_book.py
+++ b/src/calibre/gui2/viewer/convert_book.py
@@ -7,7 +7,6 @@ from __future__ import absolute_import, division, print_function, unicode_litera
 import errno
 import json
 import os
-import shutil
 import tempfile
 import time
 from hashlib import sha1
@@ -16,6 +15,7 @@ from calibre import walk
 from calibre.constants import cache_dir, iswindows
 from calibre.ptempfile import TemporaryFile
 from calibre.srv.render_book import RENDER_VERSION
+from calibre.utils.filenames import rmtree
 from calibre.utils.ipc.simple_worker import start_pipe_worker
 from calibre.utils.lock import ExclusiveFile
 from calibre.utils.serialize import msgpack_dumps
@@ -55,7 +55,7 @@ def robust_rmtree(x):
     retries = 2 if iswindows else 1  # retry on windows to get around the idiotic mandatory file locking
     for i in range(retries):
         try:
-            shutil.rmtree(x)
+            rmtree(x)
             return True
         except EnvironmentError:
             time.sleep(0.1)
@@ -297,7 +297,7 @@ def find_tests():
             book_cache_dir.override = os.path.join(self.tdir, 'ev2')
 
         def tearDown(self):
-            shutil.rmtree(self.tdir)
+            rmtree(self.tdir)
             del book_cache_dir.override
 
         def test_viewer_cache(self):
diff --git a/src/calibre/srv/books.py b/src/calibre/srv/books.py
index 61bfee301e..25a6d5c0ce 100644
--- a/src/calibre/srv/books.py
+++ b/src/calibre/srv/books.py
@@ -7,7 +7,6 @@ from __future__ import absolute_import, division, print_function, unicode_litera
 import errno
 import json as jsonlib
 import os
-import shutil
 import tempfile
 import time
 from functools import partial
@@ -21,6 +20,7 @@ from calibre.srv.metadata import book_as_json
 from calibre.srv.render_book import RENDER_VERSION
 from calibre.srv.routes import endpoint, json
 from calibre.srv.utils import get_db, get_library_data
+from calibre.utils.filenames import rmtree
 from calibre.utils.serialize import json_dumps
 from polyglot.builtins import as_unicode, map
 
@@ -66,7 +66,7 @@ def safe_remove(x, is_file=None):
     if is_file is None:
         is_file = os.path.isfile(x)
     try:
-        os.remove(x) if is_file else shutil.rmtree(x, ignore_errors=True)
+        os.remove(x) if is_file else rmtree(x, ignore_errors=True)
     except EnvironmentError:
         pass
 
diff --git a/src/calibre/srv/render_book.py b/src/calibre/srv/render_book.py
index af5ffb9c0d..21857f7705 100644
--- a/src/calibre/srv/render_book.py
+++ b/src/calibre/srv/render_book.py
@@ -7,7 +7,6 @@ from __future__ import absolute_import, division, print_function, unicode_litera
 import json
 import os
 import re
-import shutil
 import sys
 import time
 from collections import defaultdict
@@ -15,10 +14,10 @@ from datetime import datetime
 from functools import partial
 from itertools import count
 from math import ceil
-from lxml.etree import Comment
 
 from css_parser import replaceUrls
 from css_parser.css import CSSRule
+from lxml.etree import Comment
 
 from calibre import detect_ncpus, force_unicode, prepare_string_for_xml
 from calibre.constants import iswindows, plugins
@@ -41,6 +40,7 @@ from calibre.ptempfile import PersistentTemporaryDirectory
 from calibre.srv.metadata import encode_datetime
 from calibre.srv.opts import grouper
 from calibre.utils.date import EPOCH
+from calibre.utils.filenames import rmtree
 from calibre.utils.ipc.simple_worker import start_pipe_worker
 from calibre.utils.iso8601 import parse_iso8601
 from calibre.utils.logging import default_log
@@ -448,11 +448,11 @@ class RenderManager(object):
                     p.kill()
         del self.workers
         try:
-            shutil.rmtree(self.tdir)
+            rmtree(self.tdir)
         except EnvironmentError:
             time.sleep(0.1)
             try:
-                shutil.rmtree(self.tdir)
+                rmtree(self.tdir)
             except EnvironmentError:
                 pass
         del self.tdir
diff --git a/src/calibre/utils/filenames.py b/src/calibre/utils/filenames.py
index 93236af4f5..2be2f9234d 100644
--- a/src/calibre/utils/filenames.py
+++ b/src/calibre/utils/filenames.py
@@ -12,7 +12,7 @@ from math import ceil
 
 from calibre import force_unicode, isbytestring, prints, sanitize_file_name
 from calibre.constants import (
-    filesystem_encoding, iswindows, plugins, preferred_encoding, isosx
+    filesystem_encoding, iswindows, plugins, preferred_encoding, isosx, ispy3
 )
 from calibre.utils.localization import get_udc
 from polyglot.builtins import iteritems, itervalues, unicode_type, range
@@ -627,3 +627,16 @@ def copytree_using_links(path, dest, dest_is_parent=True, filecopyfunc=copyfile)
                 hardlink(src, df)
             except Exception:
                 filecopyfunc(src, df)
+
+
+if not ispy3 and not iswindows:
+    # On POSIX in python2 if you pass a unicode path to rmtree
+    # it tries to decode all filenames it encounters while walking
+    # the tree which leads to unicode errors on Linux where there
+    # can be non-decodeable filenames.
+    def rmtree(x, **kw):
+        if not isinstance(x, bytes):
+            x = x.encode('utf-8')
+        return shutil.rmtree(x, **kw)
+else:
+    rmtree = shutil.rmtree