diff --git a/monitor/batteryIcon.py b/monitor/batteryIcon.py
index 63d7f91..01b6a53 100755
--- a/monitor/batteryIcon.py
+++ b/monitor/batteryIcon.py
@@ -108,14 +108,48 @@ def make_battery_icon(percent, charging):
     return QIcon(pix)
 
 
+def tray_host_ready():
+    """True once a StatusNotifier tray host is registered on the session bus.
+
+    Queried over D-Bus directly instead of via
+    QSystemTrayIcon.isSystemTrayAvailable(): Qt caches that result from the
+    moment QApplication is constructed. At login the icon's autostart usually
+    wins the race against wf-panel-pi, so Qt caches "no tray" forever and the
+    icon never appears even after the panel's tray comes up. Checking the bus
+    directly dodges that cache -- we build QApplication only once the host is
+    actually present.
+    """
+    try:
+        result = subprocess.run(
+            ["dbus-send", "--session", "--print-reply",
+             "--dest=org.freedesktop.DBus", "/org/freedesktop/DBus",
+             "org.freedesktop.DBus.NameHasOwner",
+             "string:org.kde.StatusNotifierWatcher"],
+            capture_output=True, text=True, timeout=5)
+    except (subprocess.SubprocessError, OSError):
+        return False
+    return "boolean true" in result.stdout
+
+
+def wait_for_tray(timeout=180):
+    """Block until a tray host appears, so autostart survives a cold boot."""
+    deadline = time.monotonic() + timeout
+    while not tray_host_ready():
+        if time.monotonic() > deadline:
+            print(f"Tray host not available after {timeout}s", file=sys.stderr)
+            sys.exit(1)
+        time.sleep(2)
+
+
 class BatteryTray:
     def __init__(self):
         self.app = QApplication(sys.argv)
         self.app.setQuitOnLastWindowClosed(False)
 
-        # At login the panel may not have started its system tray yet.
-        # Wait for it instead of giving up, so autostart works after a reboot.
-        deadline = time.monotonic() + 120
+        # wait_for_tray() already confirmed a tray host on the bus, so Qt now
+        # reports the tray correctly. Keep a short re-check as a guard against
+        # the host still finishing its own registration.
+        deadline = time.monotonic() + 60
         while not QSystemTrayIcon.isSystemTrayAvailable():
             if time.monotonic() > deadline:
                 print("System tray not available after 120s", file=sys.stderr)
@@ -208,6 +242,7 @@ class BatteryTray:
 
 
 def main():
+    wait_for_tray()
     bt = BatteryTray()
     sys.exit(bt.run())