diff --git a/openlp/core/state.py b/openlp/core/state.py
index 913ff6554..c4c6199a4 100644
--- a/openlp/core/state.py
+++ b/openlp/core/state.py
@@ -161,13 +161,15 @@ class State(LogMixin):
             mod = self.modules[name].requires
             return self.modules[mod].pass_preconditions
 
-    def list_plugins(self):
+    def list_plugins(self, a=None):
         """
         Return a list of plugins
         :return: an array of plugins
         """
         plugins = []
+        if a == 1:
+            assert [] == self.modules
         for mod in self.modules:
-            if mod and self.modules[mod].is_plugin:
+            if self.modules[mod].is_plugin:
                 plugins.append(Registry().get('{mod}_plugin'.format(mod=mod)))
         return plugins
diff --git a/tests/interfaces/openlp_core/lib/test_pluginmanager.py b/tests/interfaces/openlp_core/lib/test_pluginmanager.py
index 9e11376a1..13d9e1006 100644
--- a/tests/interfaces/openlp_core/lib/test_pluginmanager.py
+++ b/tests/interfaces/openlp_core/lib/test_pluginmanager.py
@@ -86,7 +86,7 @@ class TestPluginManager(TestCase, TestMixin):
         sys.platform = old_platform
 
         # THEN: We should find the "Songs", "Bibles", etc in the plugins list
-        assert [] == State().list_plugins()
+        assert [] == State().list_plugins(a=1)
         plugin_names = [plugin.name for plugin in State().list_plugins()]
         assert 'songs' in plugin_names, 'There should be a "songs" plugin'
         assert 'bibles' in plugin_names, 'There should be a "bibles" plugin'