diff --git a/openlp/plugins/presentations/lib/impresscontroller.py b/openlp/plugins/presentations/lib/impresscontroller.py
index 935dddaaa..905b62def 100644
--- a/openlp/plugins/presentations/lib/impresscontroller.py
+++ b/openlp/plugins/presentations/lib/impresscontroller.py
@@ -93,7 +93,7 @@ class ImpressController(object):
         else:
             desktop = self.getUNODesktop()
             url = uno.systemPathToFileUrl(presentation)
-        if desktop==None:
+        if desktop is None:
             return
         try:
             properties = []