diff --git a/src/calibre/linux.py b/src/calibre/linux.py
index 1686f66b22..00f636a30f 100644
--- a/src/calibre/linux.py
+++ b/src/calibre/linux.py
@@ -40,6 +40,46 @@ entry_points = {
                             ],
       }
 
+class PreserveMIMEDefaults(object):
+
+    def __init__(self):
+        self.initial_values = {}
+
+    def __enter__(self):
+        def_data_dirs = '/usr/local/share:/usr/share'
+        paths = os.environ.get('XDG_DATA_DIRS', def_data_dirs)
+        paths = paths.split(':')
+        paths.append(os.environ.get('XDG_DATA_HOME', os.path.expanduser(
+            '~/.local/share')))
+        paths = list(filter(os.path.isdir, paths))
+        if not paths:
+            # Env var had garbage in it, ignore it
+            paths = def_data_dirs.split(':')
+        paths = list(filter(os.path.isdir, paths))
+        self.paths = {os.path.join(x, 'applications/defaults.list') for x in
+                paths}
+        self.initial_values = {}
+        for x in self.paths:
+            try:
+                with open(x, 'rb') as f:
+                    self.initial_values[x] = f.read()
+            except:
+                self.initial_values[x] = None
+
+    def __exit__(self, *args):
+        for path, val in self.initial_values.iteritems():
+            if val is None:
+                try:
+                    os.remove(path)
+                except:
+                    pass
+            elif os.path.exists(path):
+                with open(path, 'r+b') as f:
+                    if f.read() != val:
+                        f.seek(0)
+                        f.truncate()
+                        f.write(val)
+
 # Uninstall script {{{
 UNINSTALL = '''\
 #!{python}
@@ -333,57 +373,55 @@ class PostInstall:
 
     def setup_desktop_integration(self): # {{{
         try:
-
             self.info('Setting up desktop integration...')
 
+            with TemporaryDirectory() as tdir, CurrentDir(tdir), \
+                                PreserveMIMEDefaults():
+                render_img('mimetypes/lrf.png', 'calibre-lrf.png')
+                check_call('xdg-icon-resource install --noupdate --context mimetypes --size 128 calibre-lrf.png application-lrf', shell=True)
+                self.icon_resources.append(('mimetypes', 'application-lrf', '128'))
+                check_call('xdg-icon-resource install --noupdate --context mimetypes --size 128 calibre-lrf.png text-lrs', shell=True)
+                self.icon_resources.append(('mimetypes', 'application-lrs',
+                '128'))
+                render_img('lt.png', 'calibre-gui.png')
+                check_call('xdg-icon-resource install --noupdate --size 128 calibre-gui.png calibre-gui', shell=True)
+                self.icon_resources.append(('apps', 'calibre-gui', '128'))
+                render_img('viewer.png', 'calibre-viewer.png')
+                check_call('xdg-icon-resource install --size 128 calibre-viewer.png calibre-viewer', shell=True)
+                self.icon_resources.append(('apps', 'calibre-viewer', '128'))
 
-            with TemporaryDirectory() as tdir:
-                with CurrentDir(tdir):
-                    render_img('mimetypes/lrf.png', 'calibre-lrf.png')
-                    check_call('xdg-icon-resource install --noupdate --context mimetypes --size 128 calibre-lrf.png application-lrf', shell=True)
-                    self.icon_resources.append(('mimetypes', 'application-lrf', '128'))
-                    check_call('xdg-icon-resource install --noupdate --context mimetypes --size 128 calibre-lrf.png text-lrs', shell=True)
-                    self.icon_resources.append(('mimetypes', 'application-lrs',
-                    '128'))
-                    render_img('lt.png', 'calibre-gui.png')
-                    check_call('xdg-icon-resource install --noupdate --size 128 calibre-gui.png calibre-gui', shell=True)
-                    self.icon_resources.append(('apps', 'calibre-gui', '128'))
-                    render_img('viewer.png', 'calibre-viewer.png')
-                    check_call('xdg-icon-resource install --size 128 calibre-viewer.png calibre-viewer', shell=True)
-                    self.icon_resources.append(('apps', 'calibre-viewer', '128'))
+                mimetypes = set([])
+                for x in all_input_formats():
+                    mt = guess_type('dummy.'+x)[0]
+                    if mt and 'chemical' not in mt and 'ctc-posml' not in mt:
+                        mimetypes.add(mt)
 
-                    mimetypes = set([])
-                    for x in all_input_formats():
-                        mt = guess_type('dummy.'+x)[0]
-                        if mt and 'chemical' not in mt and 'ctc-posml' not in mt:
-                            mimetypes.add(mt)
+                def write_mimetypes(f):
+                    f.write('MimeType=%s;\n'%';'.join(mimetypes))
 
-                    def write_mimetypes(f):
-                        f.write('MimeType=%s;\n'%';'.join(mimetypes))
-
-                    f = open('calibre-lrfviewer.desktop', 'wb')
-                    f.write(VIEWER)
-                    f.close()
-                    f = open('calibre-ebook-viewer.desktop', 'wb')
-                    f.write(EVIEWER)
-                    write_mimetypes(f)
-                    f.close()
-                    f = open('calibre-gui.desktop', 'wb')
-                    f.write(GUI)
-                    write_mimetypes(f)
-                    f.close()
-                    des = ('calibre-gui.desktop', 'calibre-lrfviewer.desktop',
-                            'calibre-ebook-viewer.desktop')
-                    for x in des:
-                        cmd = ['xdg-desktop-menu', 'install', '--noupdate', './'+x]
-                        check_call(' '.join(cmd), shell=True)
-                        self.menu_resources.append(x)
-                    check_call(['xdg-desktop-menu', 'forceupdate'])
-                    f = open('calibre-mimetypes', 'wb')
-                    f.write(MIME)
-                    f.close()
-                    self.mime_resources.append('calibre-mimetypes')
-                    check_call('xdg-mime install ./calibre-mimetypes', shell=True)
+                f = open('calibre-lrfviewer.desktop', 'wb')
+                f.write(VIEWER)
+                f.close()
+                f = open('calibre-ebook-viewer.desktop', 'wb')
+                f.write(EVIEWER)
+                write_mimetypes(f)
+                f.close()
+                f = open('calibre-gui.desktop', 'wb')
+                f.write(GUI)
+                write_mimetypes(f)
+                f.close()
+                des = ('calibre-gui.desktop', 'calibre-lrfviewer.desktop',
+                        'calibre-ebook-viewer.desktop')
+                for x in des:
+                    cmd = ['xdg-desktop-menu', 'install', '--noupdate', './'+x]
+                    check_call(' '.join(cmd), shell=True)
+                    self.menu_resources.append(x)
+                check_call(['xdg-desktop-menu', 'forceupdate'])
+                f = open('calibre-mimetypes', 'wb')
+                f.write(MIME)
+                f.close()
+                self.mime_resources.append('calibre-mimetypes')
+                check_call('xdg-mime install ./calibre-mimetypes', shell=True)
         except Exception:
             if self.opts.fatal_errors:
                 raise