diff --git a/src/message_processor.py b/src/message_processor.py
index 0cbdd1d..0a259e1 100644
--- a/src/message_processor.py
+++ b/src/message_processor.py
@@ -144,7 +144,7 @@ def process_high_temp(box_name, context, local_context, payload):
 def process_window(box_name, context, local_context, sub_key, payload):
     # default converter
     converter = lambda x:x
-    for sk in box["windows"]:
+    for sk in context["boxes"][box_name]["windows"]:
         if sk["label"] == sub_key:
             converter = CONVERTERS["window_contact_input"][sk["converter"]]
             break