diff --git a/satellite/satellite.py b/satellite/satellite.py
index ee40f5c..3aba7dd 100644
--- a/satellite/satellite.py
+++ b/satellite/satellite.py
@@ -469,18 +469,28 @@ def _discover_mdns(timeout: float) -> list[dict]:
             pass
 
     zc = None
+    browsers = []
     try:
         zc = Zeroconf()
         listener = _Listener()
         for t in MDNS_TYPES:
             try:
-                ServiceBrowser(zc, t, listener)
+                browsers.append(ServiceBrowser(zc, t, listener))
             except Exception:
                 pass
         time.sleep(timeout)
     except Exception as exc:
         logger.warning("mDNS-Sweep-Fehler: %s", exc)
     finally:
+        # Jeder ServiceBrowser ist ein eigener Thread, den zc.close() NICHT
+        # beendet — ohne cancel() blieben pro Scan 14 Threads liegen. Nach
+        # ~5 Tagen war das Thread-Limit des Containers voll (18.841), danach
+        # scheiterte jeder Scan mit "[Errno 11] Resource temporarily unavailable".
+        for b in browsers:
+            try:
+                b.cancel()
+            except Exception:
+                pass
         try:
             if zc:
                 zc.close()