diff --git a/plinth/modules/mediawiki/__init__.py b/plinth/modules/mediawiki/__init__.py
index 5dd860795..f2215ab09 100644
--- a/plinth/modules/mediawiki/__init__.py
+++ b/plinth/modules/mediawiki/__init__.py
@@ -157,7 +157,11 @@ def get_server_url():
     return urlparse(server_url).netloc
 
 
-def set_server_url(server_url):
+def set_server_url(domain):
     """Set the value of $wgServer."""
+    protocol = 'https'
+    if domain.endswith('.onion'):
+        protocol = 'http'
+
     actions.superuser_run('mediawiki',
-                          ['set-server-url', f'https://{server_url}'])
+                          ['set-server-url', f'{protocol}://{domain}'])
diff --git a/plinth/modules/mediawiki/forms.py b/plinth/modules/mediawiki/forms.py
index eac74de63..b672865a8 100644
--- a/plinth/modules/mediawiki/forms.py
+++ b/plinth/modules/mediawiki/forms.py
@@ -6,8 +6,6 @@ FreedomBox app for configuring MediaWiki.
 import pathlib
 
 from django import forms
-from django.forms import Widget
-from django.utils.safestring import mark_safe
 from django.utils.translation import gettext_lazy as _
 
 
@@ -21,31 +19,6 @@ def get_skins():
             if skin.is_dir()]
 
 
-class PrependWidget(Widget):
-    """Widget to create input-groups with prepended text."""
-
-    def __init__(self, base_widget, data, *args, **kwargs):
-        """Initialize widget and get base instance"""
-        super(PrependWidget, self).__init__(*args, **kwargs)
-        self.base_widget = base_widget(*args, **kwargs)
-        self.data = data
-
-    def render(self, name, value, attrs=None, renderer=None):
-        """Render base widget and add bootstrap spans."""
-        attrs['class'] = 'form-control'
-        field = self.base_widget.render(name, value, attrs, renderer)
-        widget_html = '''
-            <div class="input-group">
-              <span class="input-group-prepend">
-                <span class="input-group-text">
-                  %(data)s
-                </span>
-              </span>
-              %(field)s
-            </div>'''
-        return mark_safe((widget_html) % {'field': field, 'data': self.data})
-
-
 class MediaWikiForm(forms.Form):  # pylint: disable=W0232
     """MediaWiki configuration form."""
     password = forms.CharField(
@@ -56,11 +29,11 @@ class MediaWikiForm(forms.Form):  # pylint: disable=W0232
             'Leave this field blank to keep the current password.'),
         required=False, widget=forms.PasswordInput, min_length=10)
 
-    server_url = forms.CharField(
-        label=_('Server URL'), required=False, help_text=_(
+    domain = forms.CharField(
+        label=_('Domain'), required=False, help_text=_(
             'Used by MediaWiki to generate URLs that point to the wiki '
-            'such as in footer, feeds and emails.'),
-        widget=PrependWidget(base_widget=forms.TextInput, data='https://'))
+            'such as in footer, feeds and emails. Examples: '
+            '"myfreedombox.example.org" or "example.onion".'))
 
     enable_public_registrations = forms.BooleanField(
         label=_('Enable public registrations'), required=False,
diff --git a/plinth/modules/mediawiki/tests/test_functional.py b/plinth/modules/mediawiki/tests/test_functional.py
index 4382176eb..768521950 100644
--- a/plinth/modules/mediawiki/tests/test_functional.py
+++ b/plinth/modules/mediawiki/tests/test_functional.py
@@ -6,8 +6,9 @@ Functional, browser based tests for mediawiki app.
 import pathlib
 from urllib.parse import urlparse
 
-import requests
 import pytest
+import requests
+
 from plinth.tests import functional
 from plinth.tests.functional import config
 
@@ -24,7 +25,7 @@ class TestMediawikiApp(functional.BaseAppTests):
         """Setup the app."""
         functional.login(session_browser)
         functional.install(session_browser, 'mediawiki')
-        _set_server_url(session_browser)
+        _set_domain(session_browser)
 
     def test_public_registrations(self, session_browser):
         """Test enabling public registrations."""
@@ -241,9 +242,9 @@ def __has_main_page(browser):
     return 'This page has been deleted.' not in content.text
 
 
-def _set_server_url(browser):
-    """Set the value of server url to the value in the given env_var."""
+def _set_domain(browser):
+    """Set the value of domain to the value in the given env_var."""
     functional.nav_to_module(browser, 'mediawiki')
-    server_url = urlparse(config['DEFAULT']['url']).netloc
-    browser.find_by_id('id_server_url').fill(server_url)
+    domain = urlparse(config['DEFAULT']['url']).netloc
+    browser.find_by_id('id_domain').fill(domain)
     functional.submit(browser, form_class='form-configuration')
diff --git a/plinth/modules/mediawiki/tests/test_settings.py b/plinth/modules/mediawiki/tests/test_settings.py
index e5db63689..3ffc87b18 100644
--- a/plinth/modules/mediawiki/tests/test_settings.py
+++ b/plinth/modules/mediawiki/tests/test_settings.py
@@ -63,6 +63,6 @@ def test_default_skin():
 def test_server_url():
     """Test getting and setting $wgServer."""
     assert mediawiki.get_server_url() == 'freedombox.local'
-    new_server_url = 'mydomain.freedombox.rocks'
-    mediawiki.set_server_url(new_server_url)
-    assert mediawiki.get_server_url() == new_server_url
+    new_domain = 'mydomain.freedombox.rocks'
+    mediawiki.set_server_url(new_domain)
+    assert mediawiki.get_server_url() == new_domain
diff --git a/plinth/modules/mediawiki/views.py b/plinth/modules/mediawiki/views.py
index 44401433b..e6f2203b6 100644
--- a/plinth/modules/mediawiki/views.py
+++ b/plinth/modules/mediawiki/views.py
@@ -32,7 +32,7 @@ class MediaWikiAppView(views.AppView):
             'enable_public_registrations': is_public_registration_enabled(),
             'enable_private_mode': is_private_mode_enabled(),
             'default_skin': get_default_skin(),
-            'server_url': get_server_url()
+            'domain': get_server_url()
         })
         return initial
 
@@ -93,8 +93,8 @@ class MediaWikiAppView(views.AppView):
             mediawiki.set_default_skin(new_config['default_skin'])
             messages.success(self.request, _('Default skin changed'))
 
-        if is_changed('server_url'):
-            mediawiki.set_server_url(new_config['server_url'])
-            messages.success(self.request, _('Server URL updated'))
+        if is_changed('domain'):
+            mediawiki.set_server_url(new_config['domain'])
+            messages.success(self.request, _('Domain name updated'))
 
         return super().form_valid(form)