diff --git a/ogn/collect/receiver.py b/ogn/collect/receiver.py
index 10b10cd..b2a5317 100644
--- a/ogn/collect/receiver.py
+++ b/ogn/collect/receiver.py
@@ -18,44 +18,58 @@ def update_receivers():
     last_entry_sq = app.session.query(coalesce(func.max(Receiver.lastseen), '2015-01-01 00:00:00').label('last_entry')) \
                                .subquery()
 
-    last_receiver_beacon_sq = app.session.query(ReceiverBeacon.name, func.min(ReceiverBeacon.timestamp).label('firstseen'), func.max(ReceiverBeacon.timestamp).label('lastseen')) \
-                                 .filter(ReceiverBeacon.timestamp >= last_entry_sq.c.last_entry) \
-                                 .group_by(ReceiverBeacon.name) \
-                                 .subquery()
+    last_receiver_beacon_sq = app.session.query(ReceiverBeacon.name,
+                                                func.min(ReceiverBeacon.timestamp).label('firstseen'),
+                                                func.max(ReceiverBeacon.timestamp).label('lastseen')) \
+                                         .filter(ReceiverBeacon.timestamp >= last_entry_sq.columns.last_entry) \
+                                         .group_by(ReceiverBeacon.name) \
+                                         .subquery()
 
     # update existing receivers
-    sq = app.session.query(ReceiverBeacon.name, ReceiverBeacon.latitude, ReceiverBeacon.longitude, ReceiverBeacon.altitude, last_receiver_beacon_sq.c.firstseen, last_receiver_beacon_sq.c.lastseen, ReceiverBeacon.version, ReceiverBeacon.platform) \
-            .filter(and_(ReceiverBeacon.name == last_receiver_beacon_sq.c.name, ReceiverBeacon.timestamp == last_receiver_beacon_sq.c.lastseen)) \
-            .subquery()
+    sq = app.session.query(ReceiverBeacon.name,
+                           ReceiverBeacon.latitude,
+                           ReceiverBeacon.longitude,
+                           ReceiverBeacon.altitude,
+                           last_receiver_beacon_sq.columns.firstseen,
+                           last_receiver_beacon_sq.columns.lastseen,
+                           ReceiverBeacon.version,
+                           ReceiverBeacon.platform) \
+                    .filter(and_(ReceiverBeacon.name == last_receiver_beacon_sq.columns.name,
+                                 ReceiverBeacon.timestamp == last_receiver_beacon_sq.columns.lastseen)) \
+                    .subquery()
 
-    # -set country code to None if lat or lon changed
+    # set country code to None if lat or lon changed
     upd = app.session.query(Receiver) \
-                     .filter(and_(Receiver.name == sq.c.name,
-                                  or_(Receiver.latitude != sq.c.latitude,
-                                      Receiver.longitude != sq.c.longitude)
-                                  )
-                             ) \
-                     .update({"latitude": sq.c.latitude,
-                              "longitude": sq.c.longitude,
-                              "country_code": None})
+                     .filter(and_(Receiver.name == sq.columns.name,
+                                  or_(Receiver.latitude != sq.columns.latitude,
+                                      Receiver.longitude != sq.columns.longitude))) \
+                     .update({"latitude": sq.columns.latitude,
+                              "longitude": sq.columns.longitude,
+                              "country_code": ""})
 
     logger.info("Count of receivers who changed lat or lon: {}".format(upd))
     app.session.commit()
 
-    # -update lastseen of known receivers
+    # update lastseen of known receivers
     upd = app.session.query(Receiver) \
-                     .filter(Receiver.name == sq.c.name) \
-                     .update({"altitude": sq.c.altitude,
-                              "lastseen": sq.c.lastseen,
-                              "version": sq.c.version,
-                              "platform": sq.c.platform})
+                     .filter(Receiver.name == sq.columns.name) \
+                     .update({"altitude": sq.columns.altitude,
+                              "lastseen": sq.columns.lastseen,
+                              "version": sq.columns.version,
+                              "platform": sq.columns.platform})
 
     logger.info("Count of receivers who where updated: {}".format(upd))
 
     # add new receivers
-    empty_sq = app.session.query(ReceiverBeacon.name, ReceiverBeacon.latitude, ReceiverBeacon.longitude, ReceiverBeacon.altitude, last_receiver_beacon_sq.c.firstseen, last_receiver_beacon_sq.c.lastseen, ReceiverBeacon.version, ReceiverBeacon.platform) \
-                          .filter(and_(ReceiverBeacon.name == last_receiver_beacon_sq.c.name,
-                                       ReceiverBeacon.timestamp == last_receiver_beacon_sq.c.lastseen)) \
+    empty_sq = app.session.query(ReceiverBeacon.name,
+                                 ReceiverBeacon.latitude,
+                                 ReceiverBeacon.longitude,
+                                 ReceiverBeacon.altitude,
+                                 last_receiver_beacon_sq.columns.firstseen,
+                                 last_receiver_beacon_sq.columns.lastseen,
+                                 ReceiverBeacon.version, ReceiverBeacon.platform) \
+                          .filter(and_(ReceiverBeacon.name == last_receiver_beacon_sq.columns.name,
+                                       ReceiverBeacon.timestamp == last_receiver_beacon_sq.columns.lastseen)) \
                           .outerjoin(Receiver, Receiver.name == ReceiverBeacon.name) \
                           .filter(Receiver.name == null()) \
                           .order_by(ReceiverBeacon.name)