diff --git a/homeassistant/components/tradfri/config_flow.py b/homeassistant/components/tradfri/config_flow.py
index 4de43c79e0c655..8d8f9af79e6387 100644
--- a/homeassistant/components/tradfri/config_flow.py
+++ b/homeassistant/components/tradfri/config_flow.py
@@ -95,7 +95,9 @@ async def async_step_import(self, user_input):
 
         try:
             data = await get_gateway_info(
-                self.hass, user_input['host'], user_input['identity'],
+                self.hass, user_input['host'],
+                # Old config format had a fixed identity
+                user_input.get('identity', 'homeassistant'),
                 user_input['key'])
 
             data[CONF_IMPORT_GROUPS] = user_input[CONF_IMPORT_GROUPS]
diff --git a/tests/components/tradfri/test_config_flow.py b/tests/components/tradfri/test_config_flow.py
index 4650fb5d9bc11e..580e9580d76eef 100644
--- a/tests/components/tradfri/test_config_flow.py
+++ b/tests/components/tradfri/test_config_flow.py
@@ -154,3 +154,34 @@ async def test_import_connection(hass, mock_gateway_info, mock_entry_setup):
 
     assert len(mock_gateway_info.mock_calls) == 1
     assert len(mock_entry_setup.mock_calls) == 1
+
+
+async def test_import_connection_legacy(hass, mock_gateway_info,
+                                        mock_entry_setup):
+    """Test a connection via import."""
+    mock_gateway_info.side_effect = \
+        lambda hass, host, identity, key: mock_coro({
+            'host': host,
+            'identity': identity,
+            'key': key,
+            'gateway_id': 'mock-gateway'
+        })
+
+    result = await hass.config_entries.flow.async_init(
+        'tradfri', context={'source': 'import'}, data={
+            'host': '123.123.123.123',
+            'key': 'mock-key',
+            'import_groups': True
+        })
+
+    assert result['type'] == data_entry_flow.RESULT_TYPE_CREATE_ENTRY
+    assert result['result'].data == {
+        'host': '123.123.123.123',
+        'gateway_id': 'mock-gateway',
+        'identity': 'homeassistant',
+        'key': 'mock-key',
+        'import_groups': True
+    }
+
+    assert len(mock_gateway_info.mock_calls) == 1
+    assert len(mock_entry_setup.mock_calls) == 1