diff --git a/bypy/macos/site.py b/bypy/macos/site.py
index b017184ad3..ecc8f0463d 100644
--- a/bypy/macos/site.py
+++ b/bypy/macos/site.py
@@ -21,8 +21,8 @@ def read_user_env_vars():
 
 def nuke_stdout():
     # Redirect stdout, stdin and stderr to /dev/null
-    from calibre.constants import plugins
-    plugins['speedup'][0].detach(os.devnull)
+    from calibre_extensions.speedup import detach
+    detach(os.devnull)
 
 
 def set_helper():
diff --git a/src/calibre/gui2/open_with.py b/src/calibre/gui2/open_with.py
index d5f2f5ac92..92ff86a6a8 100644
--- a/src/calibre/gui2/open_with.py
+++ b/src/calibre/gui2/open_with.py
@@ -68,7 +68,7 @@ if iswindows:
     # Windows {{{
     from calibre.utils.winreg.default_programs import find_programs, friendly_app_name
     from calibre.utils.open_with.windows import load_icon_resource, load_icon_for_cmdline
-    from calibre.constants import plugins
+    from calibre_extensions import winutil
     import subprocess
     oprefs = JSONConfig('windows_open_with')
 
@@ -145,7 +145,7 @@ if iswindows:
         print('Running Open With commandline%s:' % console, repr(entry['cmdline']), ' |==> ', repr(cmdline))
         try:
             with sanitize_env_vars():
-                plugins['winutil'][0].run_cmdline(cmdline, flags, 2000)
+                winutil.run_cmdline(cmdline, flags, 2000)
         except Exception as err:
             return error_dialog(
                 parent, _('Failed to run'), _(
diff --git a/src/calibre/gui2/progress_indicator/__init__.py b/src/calibre/gui2/progress_indicator/__init__.py
index 87d86cb183..5a728391c2 100644
--- a/src/calibre/gui2/progress_indicator/__init__.py
+++ b/src/calibre/gui2/progress_indicator/__init__.py
@@ -7,15 +7,11 @@ from PyQt5.Qt import (
     QWidget
 )
 
-from calibre.constants import plugins
+from calibre_extensions.progress_indicator import (
+    QProgressIndicator as ProgressIndicator, draw_snake_spinner
+)
 
-pi, err = plugins['progress_indicator']
-if err:
-    raise RuntimeError('Failed to import the progress_indicator plugin with error: {}'.format(err))
-
-
-ProgressIndicator = pi.QProgressIndicator
-draw_snake_spinner = pi.draw_snake_spinner
+draw_snake_spinner
 
 
 class WaitPanel(QWidget):
diff --git a/src/calibre/utils/cleantext.py b/src/calibre/utils/cleantext.py
index 9b272288ab..5a0583ef6c 100644
--- a/src/calibre/utils/cleantext.py
+++ b/src/calibre/utils/cleantext.py
@@ -4,11 +4,11 @@
 
 
 import re
-from polyglot.builtins import codepoint_to_chr, map, range, filter
-from polyglot.html_entities import name2codepoint
-from calibre.constants import plugins, preferred_encoding
 
-_ncxc = plugins['speedup'][0].clean_xml_chars
+from calibre.constants import preferred_encoding
+from calibre_extensions.speedup import clean_xml_chars as _ncxc
+from polyglot.builtins import codepoint_to_chr, filter, map, range
+from polyglot.html_entities import name2codepoint
 
 
 def native_clean_xml_chars(x):
diff --git a/src/calibre/utils/date.py b/src/calibre/utils/date.py
index c877bebcb3..ae7c4e4d8d 100644
--- a/src/calibre/utils/date.py
+++ b/src/calibre/utils/date.py
@@ -11,7 +11,7 @@ from datetime import datetime, time as dtime, timedelta, MINYEAR, MAXYEAR
 from functools import partial
 
 from calibre import strftime
-from calibre.constants import iswindows, ismacos, plugins, preferred_encoding
+from calibre.constants import iswindows, ismacos, preferred_encoding
 from calibre.utils.iso8601 import utc_tz, local_tz, UNDEFINED_DATE
 from calibre.utils.localization import lcdata
 from polyglot.builtins import unicode_type, native_string_type
@@ -33,7 +33,8 @@ if iswindows:
     del ctypes, LOCALE_SSHORTDATE, buf, LOCALE_USER_DEFAULT
 elif ismacos:
     try:
-        date_fmt = plugins['usbobserver'][0].date_format()
+        from calibre_extensions.usbobserver import date_format
+        date_fmt = date_format()
         parse_date_day_first = date_fmt.index('d') < date_fmt.index('M')
     except:
         parse_date_day_first = False
diff --git a/src/calibre/utils/fonts/free_type.py b/src/calibre/utils/fonts/free_type.py
index 1a62d34652..d588dc49c1 100644
--- a/src/calibre/utils/fonts/free_type.py
+++ b/src/calibre/utils/fonts/free_type.py
@@ -8,9 +8,9 @@ __docformat__ = 'restructuredtext en'
 
 import threading
 from functools import wraps
-from polyglot.builtins import map, unicode_type
 
-from calibre.constants import plugins
+from calibre_extensions.freetype import FreeType as _FreeType
+from polyglot.builtins import map, unicode_type
 
 
 class ThreadingViolation(Exception):
@@ -30,9 +30,6 @@ def same_thread(func):
     return check_thread
 
 
-FreeTypeError = getattr(plugins['freetype'][0], 'FreeTypeError', Exception)
-
-
 class Face(object):
 
     def __init__(self, face):
@@ -71,11 +68,7 @@ class FreeType(object):
 
     def __init__(self):
         self.start_thread = threading.current_thread()
-        ft, ft_err = plugins['freetype']
-        if ft_err:
-            raise RuntimeError('Failed to load FreeType module with error: %s'
-                    % ft_err)
-        self.ft = ft.FreeType()
+        self.ft = _FreeType()
 
     @same_thread
     def load_font(self, data):
diff --git a/src/calibre/utils/fonts/scanner.py b/src/calibre/utils/fonts/scanner.py
index 94baa9312d..98b367b8f8 100644
--- a/src/calibre/utils/fonts/scanner.py
+++ b/src/calibre/utils/fonts/scanner.py
@@ -11,7 +11,7 @@ from collections import defaultdict
 from threading import Thread
 
 from calibre import walk, prints, as_unicode
-from calibre.constants import (config_dir, iswindows, ismacos, plugins, DEBUG,
+from calibre.constants import (config_dir, iswindows, ismacos, DEBUG,
         isworker, filesystem_encoding)
 from calibre.utils.fonts.metadata import FontMetadata, UnsupportedFont
 from calibre.utils.icu import sort_key
@@ -100,9 +100,7 @@ def fc_list():
 
 def font_dirs():
     if iswindows:
-        winutil, err = plugins['winutil']
-        if err:
-            raise RuntimeError('Failed to load winutil: %s'%err)
+        from calibre_extensions import winutil
         paths = {os.path.normcase(r'C:\Windows\Fonts')}
         for which in (winutil.CSIDL_FONTS, winutil.CSIDL_LOCAL_APPDATA, winutil.CSIDL_APPDATA):
             try:
diff --git a/src/calibre/utils/iso8601.py b/src/calibre/utils/iso8601.py
index 78d9954206..09acabda09 100644
--- a/src/calibre/utils/iso8601.py
+++ b/src/calibre/utils/iso8601.py
@@ -6,11 +6,7 @@
 from datetime import datetime
 
 from dateutil.tz import tzlocal, tzutc, tzoffset
-
-from calibre.constants import plugins
-speedup, err = plugins['speedup']
-if not speedup:
-    raise RuntimeError(err)
+from calibre_extensions import speedup
 
 
 class SafeLocalTimeZone(tzlocal):
diff --git a/src/calibre/utils/podofo/__init__.py b/src/calibre/utils/podofo/__init__.py
index 92f6286dfb..306a53eca3 100644
--- a/src/calibre/utils/podofo/__init__.py
+++ b/src/calibre/utils/podofo/__init__.py
@@ -7,7 +7,7 @@ import os
 import shutil
 import sys
 
-from calibre.constants import plugins, preferred_encoding
+from calibre.constants import preferred_encoding
 from calibre.ebooks.metadata import authors_to_string
 from calibre.ptempfile import TemporaryDirectory
 from calibre.utils.ipc.simple_worker import WorkerError, fork_job
@@ -15,9 +15,7 @@ from polyglot.builtins import unicode_type
 
 
 def get_podofo():
-    podofo, podofo_err = plugins['podofo']
-    if podofo is None:
-        raise RuntimeError('Failed to load podofo: %s'%podofo_err)
+    from calibre_extensions import podofo
     return podofo
 
 
diff --git a/src/calibre/utils/recycle_bin.py b/src/calibre/utils/recycle_bin.py
index 6f2742ebc8..ed28767b18 100644
--- a/src/calibre/utils/recycle_bin.py
+++ b/src/calibre/utils/recycle_bin.py
@@ -9,7 +9,7 @@ __docformat__ = 'restructuredtext en'
 import os, shutil, time, sys
 
 from calibre import isbytestring
-from calibre.constants import (iswindows, ismacos, plugins, filesystem_encoding,
+from calibre.constants import (iswindows, ismacos, filesystem_encoding,
         islinux)
 from polyglot.builtins import unicode_type
 
@@ -18,6 +18,7 @@ recycle = None
 if iswindows:
     from calibre.utils.ipc import eintr_retry_call
     from threading import Lock
+    from calibre_extensions import winutil
     recycler = None
     rlock = Lock()
 
@@ -28,7 +29,7 @@ if iswindows:
             recycler = start_pipe_worker('from calibre.utils.recycle_bin import recycler_main; recycler_main()')
 
     def recycle_path(path):
-        plugins['winutil'][0].move_to_trash(unicode_type(path))
+        winutil.move_to_trash(unicode_type(path))
 
     def recycler_main():
         stdin = getattr(sys.stdin, 'buffer', sys.stdin)
@@ -86,13 +87,13 @@ if iswindows:
         return delegate_recycle(path)
 
 elif ismacos:
-    u = plugins['cocoa'][0]
-    if hasattr(u, 'send2trash'):
-        def osx_recycle(path):
-            if isbytestring(path):
-                path = path.decode(filesystem_encoding)
-            u.send2trash(path)
-        recycle = osx_recycle
+    from calibre_extensions.cocoa import send2trash
+
+    def osx_recycle(path):
+        if isbytestring(path):
+            path = path.decode(filesystem_encoding)
+        send2trash(path)
+    recycle = osx_recycle
 elif islinux:
     from calibre.utils.linux_trash import send2trash