diff --git a/plexpy/notification_handler.py b/plexpy/notification_handler.py
index 497973be..ed4e60b3 100644
--- a/plexpy/notification_handler.py
+++ b/plexpy/notification_handler.py
@@ -339,9 +339,15 @@ def notify_custom_conditions(notifier_id=None, parameters=None):
             elif operator == 'begins with':
                 evaluated = parameter_value.startswith(tuple(values))
 
+            elif operator == 'does not begin with':
+                evaluated = not parameter_value.startswith(tuple(values))
+
             elif operator == 'ends with':
                 evaluated = parameter_value.endswith(tuple(values))
 
+            elif operator == 'does not end with':
+                evaluated = not parameter_value.endswith(tuple(values))
+
             elif operator == 'is greater than':
                 evaluated = any(parameter_value > c for c in values)