diff --git a/zont-exporter/zont_exporter.py b/zont-exporter/zont_exporter.py
index de7ad51..4c8aad6 100644
--- a/zont-exporter/zont_exporter.py
+++ b/zont-exporter/zont_exporter.py
@@ -519,10 +519,13 @@ def collect_events(did):
                 'type_ru': type_ru,
                 'alarm': bool(is_alarm),
                 'description': description,
-                'lat': lat,
-                'lon': lon,
-                'duration': duration,
             }
+            if lat is not None:
+                log_obj['lat'] = lat
+            if lon is not None:
+                log_obj['lon'] = lon
+            if duration is not None:
+                log_obj['duration'] = duration
             line = json.dumps(log_obj, ensure_ascii=False)
 
             labels = {