diff --git a/src/simplified_access.py b/src/simplified_access.py
index 05134fb..e5f11b1 100644
--- a/src/simplified_access.py
+++ b/src/simplified_access.py
@@ -138,7 +138,7 @@ class CustomerFactory:
         phone_numbers = []
         if customer.telephone:
             for tel in customer.telephone:
-                phone_numbers.append((tel.phone_number, tel.phone_tech_type))
+                phone_numbers.append((tel.phone_number, PhoneTechType(tel.phone_tech_type) if tel.phone_tech_type else None))
         
         # Extract email info
         email_address = None