diff --git a/autotests/util/iwd.py b/autotests/util/iwd.py
index 3e85b9b0..687b5610 100755
--- a/autotests/util/iwd.py
+++ b/autotests/util/iwd.py
@@ -8,6 +8,7 @@ import sys
 import os
 import threading
 import time
+import collections
 
 from abc import ABCMeta, abstractmethod
 from enum import Enum
@@ -602,6 +603,39 @@ class PSKAgent(dbus.service.Object):
         return passwd
 
 
+class DeviceList(collections.Mapping):
+    def __init__(self, iwd, objects):
+        self._dict = {}
+
+        iwd._object_manager.connect_to_signal("InterfacesAdded",
+                self._interfaces_added_handler, IWD_DEVICE_INTERFACE)
+        iwd._object_manager.connect_to_signal("InterfacesRemoved",
+                self._interfaces_removed_handler, IWD_DEVICE_INTERFACE)
+
+        for path in objects:
+            for interface in objects[path]:
+                if interface == IWD_DEVICE_INTERFACE:
+                    self._dict[path] = Device(path, objects[path][interface])
+
+    def __getitem__(self, key):
+        return self._dict.__getitem__(key)
+
+    def __iter__(self):
+        return self._dict.__iter__()
+
+    def __len__(self):
+        return self._dict.__len__()
+
+    def __delitem__(self, key):
+        self._dict.pop(key).remove()
+
+    def _interfaces_added_handler(self, path, interfaces):
+        self._dict[path] = Device(interfaces[IWD_DEVICE_INTERFACE])
+
+    def _interfaces_removed_handler(self, path, interfaces):
+        del _dict[path]
+
+
 class IWD(AsyncOpAbstract):
     ''''''
     _bus = dbus.SystemBus()
@@ -610,6 +644,7 @@ class IWD(AsyncOpAbstract):
     _agent_manager_if = None
     _known_network_manager_if = None
     _iwd_proc = None
+    _devices = None
 
     def __init__(self, start_iwd_daemon = False,
                                                iwd_config_dir = IWD_CONFIG_DIR):
@@ -648,6 +683,9 @@ class IWD(AsyncOpAbstract):
                 tries += 1
             time.sleep(0.05)
 
+        self._devices = DeviceList(self,
+                                       self._object_manager.GetManagedObjects())
+
     def __del__(self):
         if self._iwd_proc is None:
             return
@@ -727,18 +765,19 @@ class IWD(AsyncOpAbstract):
         assert not os.path.isabs(source)
         shutil.copy(source, IWD_STORAGE_DIR)
 
-    def list_devices(self):
-        objects = self._object_manager.GetManagedObjects()
-        devices = None
-        for path in objects.keys():
-            interfaces = objects[path]
-            for interface in interfaces.keys():
-                if interface in [IWD_DEVICE_INTERFACE]:
-                    if devices is None:
-                        devices = []
-                    device = Device(path)
-                    devices.append(device)
-        return devices
+    def list_devices(self, wait_to_appear = False):
+        if not wait_to_appear:
+            return list(self._devices.values())
+
+        tries = 0
+        while len(self._devices) == 0:
+            if tries > 100:
+                raise TimeoutError('IWD has no associated devices')
+
+            tries += 1
+            time.sleep(0.2)
+
+        return list(self._devices.values())
 
     def list_known_networks(self):
         '''Returns a list of KnownNetwork objects.'''