diff --git a/functional_tests/features/wiki_engine.feature b/functional_tests/features/wiki_engine.feature
index d79e380cd..a3a29a580 100644
--- a/functional_tests/features/wiki_engine.feature
+++ b/functional_tests/features/wiki_engine.feature
@@ -53,3 +53,16 @@ Scenario: Disable private mode
   Given the mediawiki application is enabled
   When I disable mediawiki private mode
   Then the mediawiki site should allow anonymous reads and writes
+
+Scenario: Enabling private mode disables public registrations
+  Given the mediawiki application is enabled
+  When I enable mediawiki public registrations
+  And I enable mediawiki private mode
+  Then the mediawiki site should not allow creating accounts
+
+# Requires JS
+Scenario: Enabling public registrations disables private mode
+  Given the mediawiki application is enabled
+  When I enable mediawiki private mode
+  And I enable mediawiki public registrations
+  Then the mediawiki site should allow creating accounts
diff --git a/plinth/modules/mediawiki/templates/mediawiki.html b/plinth/modules/mediawiki/templates/mediawiki.html
new file mode 100644
index 000000000..e8481261b
--- /dev/null
+++ b/plinth/modules/mediawiki/templates/mediawiki.html
@@ -0,0 +1,41 @@
+{% extends "service.html" %}
+{% comment %}
+#
+# This file is part of FreedomBox.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+{% endcomment %}
+
+{% load i18n %}
+
+{% block page_js %}
+  <script type="text/javascript">
+   (function($) {
+       $('#id_enable_public_registrations').click(function () {
+		       var checkedState =   $(this).prop("checked");
+           if (checkedState) {
+    	         $('#id_enable_private_mode').prop('checked', false);
+  	       }
+       });
+
+       $('#id_enable_private_mode').click(function () {
+		       var checkedState =   $(this).prop("checked");
+           if (checkedState) {
+    	         $('#id_enable_public_registrations').prop('checked', false);
+  	       }
+       });
+   })(jQuery);
+  </script>
+{% endblock %}
diff --git a/plinth/modules/mediawiki/views.py b/plinth/modules/mediawiki/views.py
index dcf2c21f8..bb431e9ec 100644
--- a/plinth/modules/mediawiki/views.py
+++ b/plinth/modules/mediawiki/views.py
@@ -23,10 +23,11 @@ import logging
 from django.contrib import messages
 from django.utils.translation import ugettext as _
 
-from plinth import actions, views, frontpage
+from plinth import actions, views
 from plinth.modules import mediawiki
 
-from . import is_public_registration_enabled, is_private_mode_enabled, is_enabled, add_shortcut
+from . import (add_shortcut, is_enabled, is_private_mode_enabled,
+               is_public_registration_enabled)
 from .forms import MediaWikiForm
 
 logger = logging.getLogger(__name__)
@@ -41,6 +42,7 @@ class MediaWikiServiceView(views.ServiceView):
     form_class = MediaWikiForm
     manual_page = mediawiki.manual_page
     show_status_block = False
+    template_name = 'mediawiki.html'
 
     def get_initial(self):
         """Return the values to fill in the form."""
@@ -82,10 +84,15 @@ class MediaWikiServiceView(views.ServiceView):
         if not pub_reg_same:
             # note action public-registration restarts, if running now
             if new_config['enable_public_registrations']:
-                actions.superuser_run('mediawiki',
-                                      ['public-registrations', 'enable'])
-                messages.success(self.request,
-                                 _('Public registrations enabled'))
+                if not new_config['enable_private_mode']:
+                    actions.superuser_run('mediawiki',
+                                          ['public-registrations', 'enable'])
+                    messages.success(self.request,
+                                     _('Public registrations enabled'))
+                else:
+                    messages.warning(
+                        self.request, 'Public registrations ' +
+                        'cannot be enabled when private mode is enabled')
             else:
                 actions.superuser_run('mediawiki',
                                       ['public-registrations', 'disable'])
@@ -94,19 +101,15 @@ class MediaWikiServiceView(views.ServiceView):
 
         if not private_mode_same:
             if new_config['enable_private_mode']:
-                actions.superuser_run('mediawiki',
-                                      ['private-mode', 'enable'])
+                actions.superuser_run('mediawiki', ['private-mode', 'enable'])
                 if new_config['enable_public_registrations']:
                     # If public registrations are enabled, then disable it
                     actions.superuser_run('mediawiki',
                                           ['public-registrations', 'disable'])
-                messages.success(self.request,
-                                 _('Private mode enabled'))
+                messages.success(self.request, _('Private mode enabled'))
             else:
-                actions.superuser_run('mediawiki',
-                                      ['private-mode', 'disable'])
-                messages.success(self.request,
-                                 _('Private mode disabled'))
+                actions.superuser_run('mediawiki', ['private-mode', 'disable'])
+                messages.success(self.request, _('Private mode disabled'))
             if is_enabled():
                 add_shortcut()
         return super().form_valid(form)