diff -urNp -x '*.orig' calibre-4.20.0.org/src/calibre/linux.py calibre-4.20.0/src/calibre/linux.py
--- calibre-4.20.0.org/src/calibre/linux.py	2021-06-23 14:08:51.192699952 +0200
+++ calibre-4.20.0/src/calibre/linux.py	2021-06-23 14:08:53.186104962 +0200
@@ -875,7 +875,7 @@ class PostInstall:
         def install_single_icon(iconsrc, basename, size, context, is_last_icon=False):
             filename = f'{basename}-{size}.png'
             render_img(iconsrc, filename, width=int(size), height=int(size))
-            cmd = ['xdg-icon-resource', 'install', '--noupdate', '--context', context, '--size', str(size), filename, basename]
+            cmd = ['xdg-icon-resource', 'install', '--noupdate', '--novendor', '--context', context, '--size', str(size), filename, basename]
             if is_last_icon:
                 del cmd[2]
             cc(cmd)
@@ -941,7 +941,7 @@ class PostInstall:
 
         APPDATA = get_appdata()
         for x in des:
-            cmd = ['xdg-desktop-menu', 'install', '--noupdate', './'+x]
+            cmd = ['xdg-desktop-menu', 'install', '--noupdate', '--novendor', './'+x]
             cc(' '.join(cmd), shell=True)
             self.menu_resources.append(x)
             ak = x.partition('.')[0]
@@ -951,8 +951,7 @@ class PostInstall:
         MIME = P(MIME_BASE)
         self.mime_resources.append(MIME_BASE)
         if not getattr(self.opts, 'staged_install', False):
-            cc(['xdg-mime', 'install', MIME])
-            cc(['xdg-desktop-menu', 'forceupdate'])
+            cc(['xdg-mime', 'install', '--novendor', MIME])
         else:
             from shutil import copyfile
             copyfile(MIME, os.path.join(env['XDG_DATA_DIRS'], 'mime', 'packages', MIME_BASE))