diff --git a/tests/interfaces/__init__.py b/tests/interfaces/__init__.py
index fa6ad34f6..0b5157b46 100644
--- a/tests/interfaces/__init__.py
+++ b/tests/interfaces/__init__.py
@@ -7,3 +7,7 @@ sip.setapi(u'QTime', 2)
 sip.setapi(u'QUrl', 2)
 sip.setapi(u'QVariant', 2)
 
+from PyQt4 import QtGui
+
+# Only one QApplication can be created. Use QtGui.QApplication.instance() when you need to "create" a  QApplication.
+application = QtGui.QApplication([])
diff --git a/tests/interfaces/openlp_core_lib/test_pluginmanager.py b/tests/interfaces/openlp_core_lib/test_pluginmanager.py
index f0aac5113..89dcdac0d 100644
--- a/tests/interfaces/openlp_core_lib/test_pluginmanager.py
+++ b/tests/interfaces/openlp_core_lib/test_pluginmanager.py
@@ -26,7 +26,7 @@ class TestPluginManager(TestCase):
         Settings().set_filename(self.ini_file)
         Registry.create()
         Registry().register(u'service_list', MagicMock())
-        self.app = QtGui.QApplication([])
+        self.app = QtGui.QApplication.instance()
         self.main_window = QtGui.QMainWindow()
         Registry().register(u'main_window', self.main_window)
         self.plugins_dir = os.path.abspath(os.path.join(os.path.basename(__file__), u'..', u'openlp', u'plugins'))
diff --git a/tests/interfaces/openlp_core_ui/test_filerenamedialog.py b/tests/interfaces/openlp_core_ui/test_filerenamedialog.py
index 26c07a514..61d2da75b 100644
--- a/tests/interfaces/openlp_core_ui/test_filerenamedialog.py
+++ b/tests/interfaces/openlp_core_ui/test_filerenamedialog.py
@@ -15,7 +15,7 @@ class TestStartFileRenameForm(TestCase):
         Create the UI
         """
         Registry.create()
-        self.app = QtGui.QApplication([])
+        self.app = QtGui.QApplication.instance()
         self.main_window = QtGui.QMainWindow()
         Registry().register(u'main_window', self.main_window)
         self.form = filerenameform.FileRenameForm()
diff --git a/tests/interfaces/openlp_core_ui/test_servicemanager.py b/tests/interfaces/openlp_core_ui/test_servicemanager.py
index bb62bd6e6..db161022b 100644
--- a/tests/interfaces/openlp_core_ui/test_servicemanager.py
+++ b/tests/interfaces/openlp_core_ui/test_servicemanager.py
@@ -3,7 +3,7 @@
 """
 
 from unittest import TestCase
-from mock import MagicMock
+from mock import MagicMock, patch
 
 from PyQt4 import QtGui
 
@@ -11,17 +11,18 @@ from openlp.core.lib import Registry, ScreenList
 from openlp.core.ui.mainwindow import MainWindow
 
 
-class TestStartNoteDialog(TestCase):
+class TestServiceManager(TestCase):
 
     def setUp(self):
         """
         Create the UI
         """
         Registry.create()
-        self.app = QtGui.QApplication([])
+        self.app = QtGui.QApplication.instance()
         ScreenList.create(self.app.desktop())
         Registry().register(u'application', MagicMock())
-        self.main_window = MainWindow()
+        with patch(u'openlp.core.lib.PluginManager'):
+            self.main_window = MainWindow()
         self.service_manager = Registry().get(u'service_manager')
 
     def tearDown(self):
diff --git a/tests/interfaces/openlp_core_ui/test_servicenotedialog.py b/tests/interfaces/openlp_core_ui/test_servicenotedialog.py
index 54560f224..e04f9975d 100644
--- a/tests/interfaces/openlp_core_ui/test_servicenotedialog.py
+++ b/tests/interfaces/openlp_core_ui/test_servicenotedialog.py
@@ -17,7 +17,7 @@ class TestStartNoteDialog(TestCase):
         Create the UI
         """
         Registry.create()
-        self.app = QtGui.QApplication([])
+        self.app = QtGui.QApplication.instance()
         self.main_window = QtGui.QMainWindow()
         Registry().register(u'main_window', self.main_window)
         self.form = servicenoteform.ServiceNoteForm()
diff --git a/tests/interfaces/openlp_core_ui/test_starttimedialog.py b/tests/interfaces/openlp_core_ui/test_starttimedialog.py
index d4b9e4fb9..c09426a1f 100644
--- a/tests/interfaces/openlp_core_ui/test_starttimedialog.py
+++ b/tests/interfaces/openlp_core_ui/test_starttimedialog.py
@@ -17,7 +17,7 @@ class TestStartTimeDialog(TestCase):
         Create the UI
         """
         Registry.create()
-        self.app = QtGui.QApplication([])
+        self.app = QtGui.QApplication.instance()
         self.main_window = QtGui.QMainWindow()
         Registry().register(u'main_window', self.main_window)
         self.form = starttimeform.StartTimeForm()