diff --git a/homeassistant/components/alexa/smart_home.py b/homeassistant/components/alexa/smart_home.py
index c0a42ef8aa6..a4f0225d22d 100644
--- a/homeassistant/components/alexa/smart_home.py
+++ b/homeassistant/components/alexa/smart_home.py
@@ -1065,7 +1065,16 @@ def async_api_lock(hass, config, request, entity):
         ATTR_ENTITY_ID: entity.entity_id
     }, blocking=False)
 
-    return api_message(request)
+    # Alexa expects a lockState in the response, we don't know the actual
+    # lockState at this point but assume it is locked. It is reported
+    # correctly later when ReportState is called. The alt. to this approach
+    # is to implement DeferredResponse
+    properties = [{
+        'name': 'lockState',
+        'namespace': 'Alexa.LockController',
+        'value': 'LOCKED'
+    }]
+    return api_message(request, context={'properties': properties})
 
 
 # Not supported by Alexa yet
diff --git a/tests/components/alexa/test_smart_home.py b/tests/components/alexa/test_smart_home.py
index 96e16544438..9654c667c5f 100644
--- a/tests/components/alexa/test_smart_home.py
+++ b/tests/components/alexa/test_smart_home.py
@@ -401,11 +401,17 @@ def test_lock(hass):
     assert appliance['friendlyName'] == "Test lock"
     assert_endpoint_capabilities(appliance, 'Alexa.LockController')
 
-    yield from assert_request_calls_service(
+    _, msg = yield from assert_request_calls_service(
         'Alexa.LockController', 'Lock', 'lock#test',
         'lock.lock',
         hass)
 
+    # always return LOCKED for now
+    properties = msg['context']['properties'][0]
+    assert properties['name'] == 'lockState'
+    assert properties['namespace'] == 'Alexa.LockController'
+    assert properties['value'] == 'LOCKED'
+
 
 @asyncio.coroutine
 def test_media_player(hass):