diff --git a/backend/routes/osm.py b/backend/routes/osm.py
index d2927ce..baf653a 100644
--- a/backend/routes/osm.py
+++ b/backend/routes/osm.py
@@ -30,6 +30,9 @@ _overpass_last_req  = 0.0
 _OVERPASS_MIN_DELAY = 2.0  # Sekunden zwischen Anfragen
 _OVERPASS_UA        = 'BanYaro/1.0 (https://banyaro.app; dog-walking PWA; contact: mail@motocamp.de)'
 
+# Referenzen auf laufende Hintergrund-Tasks — verhindert GC vor Abschluss
+_bg_tasks: set = set()
+
 OSM_QUERIES = {
     'waste_basket':   '[out:json][timeout:20];node["amenity"="waste_basket"]({bbox});out;',
     'dog_park':       '[out:json][timeout:25];(way["leisure"="dog_park"]({bbox});node["leisure"="dog_park"]({bbox});way["leisure"="park"]["dog"="yes"]({bbox});node["leisure"="park"]["dog"="yes"]({bbox}););out center;',
@@ -177,11 +180,13 @@ async def get_pois(
         stale = _stale_tiles(type, tiles)
 
         if stale and not fast:
-            # Direkt in den Event-Loop einplanen — Antwort kommt sofort zurück
+            # Hintergrund-Task mit gespeicherter Referenz (GC-sicher)
             async def _bg_fetch(poi_type, stale_tiles):
                 for (x, y) in stale_tiles:
                     await _fetch_and_store_tile(poi_type, x, y)
-            asyncio.create_task(_bg_fetch(type, stale))
+            task = asyncio.create_task(_bg_fetch(type, stale))
+            _bg_tasks.add(task)
+            task.add_done_callback(_bg_tasks.discard)
 
         with db() as conn:
             reported = {