diff --git a/person_detection/base_camera.py b/person_detection/base_camera.py
index 74b8f08..a479166 100644
--- a/person_detection/base_camera.py
+++ b/person_detection/base_camera.py
@@ -56,6 +56,7 @@
     frame = None  # current frame is stored here by background thread
     last_access = 0  # time of last client access to the camera
     event = CameraEvent()
+    port = 0 # default starting port offset
 
     def __init__(self):
         """Start the background camera thread if it isn't running yet."""