diff --git a/Mailnag/common/plugins.py b/Mailnag/common/plugins.py
index f47c958..2fabbb3 100644
--- a/Mailnag/common/plugins.py
+++ b/Mailnag/common/plugins.py
@@ -233,9 +233,9 @@ def load_plugins(cfg, mailnag_controller = None, filter_names = None):
 		plugins = []
 		plugin_types = Plugin._load_plugin_types()
 		
-		for modname, t in plugin_types:			
+		for modname, t in plugin_types:
 			try:
-				if (filter_names == None) or (modname in filter_names):
+				if (filter_names is None) or (modname in filter_names):
 					p = t()
 					p.init(modname, cfg, mailnag_controller)
 					plugins.append(p)
@@ -278,7 +278,7 @@ def _load_plugin_types():
 						attr = getattr(mod, attr_name)
 						if not inspect.isclass(attr):
 							continue
-						if issubclass(attr, Plugin):
+						if issubclass(attr, Plugin) and attr != Plugin:
 							plugin_types.append((modname, attr))
 				except:
 					logging.exception("Error while opening plugin file '%s'" % f)