diff --git a/homeassistant/components/deconz/config_flow.py b/homeassistant/components/deconz/config_flow.py
index cf172ad7991..ea93cc590e2 100644
--- a/homeassistant/components/deconz/config_flow.py
+++ b/homeassistant/components/deconz/config_flow.py
@@ -18,6 +18,7 @@ from .const import CONF_BRIDGEID, DEFAULT_PORT, DOMAIN
 
 DECONZ_MANUFACTURERURL = 'http://www.dresden-elektronik.de'
 CONF_SERIAL = 'serial'
+ATTR_UUID = 'udn'
 
 
 @callback
@@ -156,25 +157,28 @@ class DeconzFlowHandler(config_entries.ConfigFlow):
         if discovery_info[ATTR_MANUFACTURERURL] != DECONZ_MANUFACTURERURL:
             return self.async_abort(reason='not_deconz_bridge')
 
-        bridgeid = discovery_info[ATTR_SERIAL]
-        gateway_entries = configured_gateways(self.hass)
+        uuid = discovery_info[ATTR_UUID].replace('uuid:', '')
+        gateways = {
+            gateway.api.config.uuid: gateway
+            for gateway in self.hass.data.get(DOMAIN, {}).values()
+        }
 
-        if bridgeid in gateway_entries:
-            entry = gateway_entries[bridgeid]
+        if uuid in gateways:
+            entry = gateways[uuid].config_entry
             await self._update_entry(entry, discovery_info[CONF_HOST])
             return self.async_abort(reason='updated_instance')
 
-        # pylint: disable=unsupported-assignment-operation
-        self.context[ATTR_SERIAL] = bridgeid
-
-        if any(bridgeid == flow['context'][ATTR_SERIAL]
+        bridgeid = discovery_info[ATTR_SERIAL]
+        if any(bridgeid == flow['context'][CONF_BRIDGEID]
                for flow in self._async_in_progress()):
             return self.async_abort(reason='already_in_progress')
 
+        # pylint: disable=unsupported-assignment-operation
+        self.context[CONF_BRIDGEID] = bridgeid
+
         deconz_config = {
             CONF_HOST: discovery_info[CONF_HOST],
             CONF_PORT: discovery_info[CONF_PORT],
-            CONF_BRIDGEID: bridgeid
         }
 
         return await self.async_step_import(deconz_config)
diff --git a/tests/components/deconz/test_config_flow.py b/tests/components/deconz/test_config_flow.py
index 2b9f2c013b0..ac22c964151 100644
--- a/tests/components/deconz/test_config_flow.py
+++ b/tests/components/deconz/test_config_flow.py
@@ -1,5 +1,5 @@
 """Tests for deCONZ config flow."""
-from unittest.mock import patch
+from unittest.mock import Mock, patch
 
 import asyncio
 
@@ -177,7 +177,8 @@ async def test_bridge_ssdp_discovery(hass):
             config_flow.CONF_PORT: 80,
             config_flow.ATTR_SERIAL: 'id',
             config_flow.ATTR_MANUFACTURERURL:
-                config_flow.DECONZ_MANUFACTURERURL
+                config_flow.DECONZ_MANUFACTURERURL,
+            config_flow.ATTR_UUID: 'uuid:1234'
         },
         context={'source': 'ssdp'}
     )
@@ -207,13 +208,19 @@ async def test_bridge_discovery_update_existing_entry(hass):
     })
     entry.add_to_hass(hass)
 
+    gateway = Mock()
+    gateway.config_entry = entry
+    gateway.api.config.uuid = '1234'
+    hass.data[config_flow.DOMAIN] = {'id': gateway}
+
     result = await hass.config_entries.flow.async_init(
         config_flow.DOMAIN,
         data={
             config_flow.CONF_HOST: 'mock-deconz',
             config_flow.ATTR_SERIAL: 'id',
             config_flow.ATTR_MANUFACTURERURL:
-                config_flow.DECONZ_MANUFACTURERURL
+                config_flow.DECONZ_MANUFACTURERURL,
+            config_flow.ATTR_UUID: 'uuid:1234'
         },
         context={'source': 'ssdp'}
     )