diff --git a/tools/test-networkmanager-service.py b/tools/test-networkmanager-service.py
index 1504dfdfd0..18f4b5ef91 100755
--- a/tools/test-networkmanager-service.py
+++ b/tools/test-networkmanager-service.py
@@ -1666,30 +1666,16 @@ class NetworkManager(ExportedObj):
             raise BusErr.UnknownConnectionException("Connection not found")
 
         con_hash = con_inst.con_hash
-        con_type = NmUtil.con_hash_get_type(con_hash)
 
-        device = self.find_device_first(path=devpath)
-        if not device:
-            if con_type == NM.SETTING_WIRED_SETTING_NAME:
-                device = self.find_device_first(dev_type=WiredDevice)
-            elif con_type == NM.SETTING_WIRELESS_SETTING_NAME:
-                device = self.find_device_first(dev_type=WifiDevice)
-            elif con_type == NM.SETTING_VLAN_SETTING_NAME:
-                ifname = con_hash[NM.SETTING_CONNECTION_SETTING_NAME]["interface-name"]
-                device = VlanDevice(ifname)
+        device = self.find_device(devpath, con_hash)
+        if device is None:
+            device = self.create_device(con_hash)
+            if device:
+                # Just created the device, it can start activating right away
+                device.activation_state_change_delay_ms = 0
                 self.add_device(device)
-            elif con_type == NM.SETTING_VPN_SETTING_NAME:
-                for ac in self.active_connections:
-                    if ac.is_vpn:
-                        continue
-                    if ac.device:
-                        device = ac.device
-                        break
-
-        if not device:
-            raise BusErr.UnknownDeviceException(
-                "No device found for the requested iface."
-            )
+        if device is None:
+            raise BusErr.UnknownDeviceException("Device not found")
 
         # See if we need secrets. For the moment, we only support WPA
         if "802-11-wireless-security" in con_hash:
@@ -1874,6 +1860,37 @@ class NetworkManager(ExportedObj):
             raise BusErr.UnknownDeviceException("Device not found")
         return r
 
+    def find_device(self, devpath, con_hash):
+        device = self.find_device_first(path=devpath)
+        if device:
+            return device
+
+        con_type = NmUtil.con_hash_get_type(con_hash)
+
+        if con_type == NM.SETTING_WIRED_SETTING_NAME:
+            return self.find_device_first(dev_type=WiredDevice)
+
+        if con_type == NM.SETTING_WIRELESS_SETTING_NAME:
+            return self.find_device_first(dev_type=WifiDevice)
+
+        if con_type == NM.SETTING_VPN_SETTING_NAME:
+            for ac in self.active_connections:
+                if ac.is_vpn:
+                    continue
+                if ac.device:
+                    return ac.device
+
+        return None
+
+    def create_device(self, con_hash):
+        con_type = NmUtil.con_hash_get_type(con_hash)
+
+        if con_type == NM.SETTING_VLAN_SETTING_NAME:
+            ifname = con_hash[NM.SETTING_CONNECTION_SETTING_NAME]["interface-name"]
+            return VlanDevice(ifname)
+
+        return None
+
     def add_device(self, device):
         if self.find_device_first(ident=device.ident, path=device.path) is not None:
             raise TestError(