diff --git a/backend/Property.py b/backend/Property.py
index ad152ff2..4b5e1304 100644
--- a/backend/Property.py
+++ b/backend/Property.py
@@ -58,7 +58,7 @@ class Property(Definitions):
         self.full_sap_epc = full_sap_epc
         self.property_dimensions = None
 
-        self.uprn = None if data is not None else data["uprn"]
+        self.uprn = None if data is None else data["uprn"]
 
         self.in_conservation_area, self.is_listed, self.is_heritage = None, None, None
         self.restricted_measures = False