diff --git a/plinth/module_loader.py b/plinth/module_loader.py
index b552d2260..78d610176 100644
--- a/plinth/module_loader.py
+++ b/plinth/module_loader.py
@@ -26,6 +26,7 @@ import os
 
 from plinth import cfg
 from plinth import urls
+from plinth.signals import pre_module_loading, post_module_loading
 
 LOGGER = logging.getLogger(__name__)
 
@@ -37,6 +38,7 @@ def load_modules():
     Read names of enabled modules in modules/enabled directory and
     import them from modules directory.
     """
+    pre_module_loading.send_robust(sender="module_loader")
     module_names = []
     modules = {}
     directory = os.path.dirname(os.path.abspath(__file__))
@@ -75,6 +77,8 @@ def load_modules():
     for module_name in ordered_modules:
         _initialize_module(modules[module_name])
         LOADED_MODULES.append(module_name)
+    post_module_loading.send_robust(sender="module_loader")
+
 
 
 def _insert_modules(module_name, module, remaining_modules, ordered_modules):
diff --git a/plinth/modules/firewall/firewall.py b/plinth/modules/firewall/firewall.py
index 5062488db..633f2d665 100644
--- a/plinth/modules/firewall/firewall.py
+++ b/plinth/modules/firewall/firewall.py
@@ -26,6 +26,7 @@ import logging
 
 from plinth import actions
 from plinth import cfg
+from plinth.signals import service_enabled
 import plinth.service as service_module
 
 
@@ -37,7 +38,7 @@ def init():
     menu = cfg.main_menu.get('system:index')
     menu.add_urlname(_('Firewall'), 'icon-flag', 'firewall:index', 50)
 
-    service_module.ENABLED.connect(on_service_enabled)
+    service_enabled.connect(on_service_enabled)
 
 
 @login_required
diff --git a/plinth/service.py b/plinth/service.py
index 30d9cdf06..a8127052f 100644
--- a/plinth/service.py
+++ b/plinth/service.py
@@ -23,7 +23,8 @@ from gettext import gettext as _
 
 import django.dispatch
 
-ENABLED = django.dispatch.Signal(providing_args=['service_id', 'enabled'])
+from plinth.signals import service_enabled
+
 
 SERVICES = {}
 
@@ -63,7 +64,7 @@ class Service(object):
         if not callable(self._enabled):
             self._enabled = enabled
 
-        ENABLED.send_robust(sender=sender, service_id=self.service_id,
+        service_enabled.send_robust(sender=sender, service_id=self.service_id,
                             enabled=enabled)
 
 
diff --git a/plinth/signals.py b/plinth/signals.py
new file mode 100644
index 000000000..f02002289
--- /dev/null
+++ b/plinth/signals.py
@@ -0,0 +1,27 @@
+#
+# This file is part of Plinth.
+#
+# 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/>.
+#
+
+"""
+Plinth signals
+"""
+
+from django.dispatch import Signal
+
+
+service_enabled = Signal(providing_args=['service_id', 'enabled'])
+pre_module_loading = Signal()
+post_module_loading = Signal()