diff --git a/ogn/collect/fetchddb.py b/ogn/collect/fetchddb.py
index f351ca6..2d17a3f 100644
--- a/ogn/collect/fetchddb.py
+++ b/ogn/collect/fetchddb.py
@@ -14,7 +14,7 @@ def update_ddb_from_ogn():
     logger.info("Update ddb data from ogn.")
 
     app.session.query(Device) \
-        .filter(Device.address_origin == AddressOrigin.ogn_ddb) \
+        .filter(AddressOrigin(Device.address_origin) is AddressOrigin.ogn_ddb) \
         .delete()
 
     devices = get_ddb()
@@ -31,7 +31,7 @@ def update_ddb_from_file():
     logger.info("Import ddb data from file.")
 
     app.session.query(Device) \
-        .filter(Device.address_origin == AddressOrigin.userdefined) \
+        .filter(AddressOrigin(Device.address_origin) is AddressOrigin.userdefined) \
         .delete()
 
     devices = get_ddb('ogn/custom_ddb.txt')
diff --git a/ogn/model/address_origin.py b/ogn/model/address_origin.py
index 8744e5e..1520e6d 100644
--- a/ogn/model/address_origin.py
+++ b/ogn/model/address_origin.py
@@ -1,4 +1,8 @@
-class AddressOrigin:
+from enum import Enum, unique
+
+
+@unique
+class AddressOrigin(Enum):
     ogn_ddb = 1
     flarmnet = 2
     userdefined = 3