diff --git a/homeassistant/components/api/__init__.py b/homeassistant/components/api/__init__.py
index a82309094e3..e40a9332c38 100644
--- a/homeassistant/components/api/__init__.py
+++ b/homeassistant/components/api/__init__.py
@@ -178,7 +178,6 @@ class APIDiscoveryView(HomeAssistantView):
     requires_auth = False
     url = URL_API_DISCOVERY_INFO
     name = "api:discovery"
-    cors_allowed = True
 
     async def get(self, request):
         """Get discovery information."""
diff --git a/homeassistant/components/http/__init__.py b/homeassistant/components/http/__init__.py
index d09cfe754a9..993d466ae18 100644
--- a/homeassistant/components/http/__init__.py
+++ b/homeassistant/components/http/__init__.py
@@ -59,7 +59,7 @@ _LOGGER = logging.getLogger(__name__)
 DEFAULT_DEVELOPMENT = "0"
 # Cast to be able to load custom cards.
 # My to be able to check url and version info.
-DEFAULT_CORS = ["https://cast.home-assistant.io", "https://my.home-assistant.io"]
+DEFAULT_CORS = ["https://cast.home-assistant.io"]
 NO_LOGIN_ATTEMPT_THRESHOLD = -1
 
 MAX_CLIENT_SIZE: int = 1024 ** 2 * 16
diff --git a/tests/components/http/test_init.py b/tests/components/http/test_init.py
index 9621b269081..993f0dba1fd 100644
--- a/tests/components/http/test_init.py
+++ b/tests/components/http/test_init.py
@@ -175,10 +175,7 @@ async def test_cors_defaults(hass):
         assert await async_setup_component(hass, "http", {})
 
     assert len(mock_setup.mock_calls) == 1
-    assert mock_setup.mock_calls[0][1][1] == [
-        "https://cast.home-assistant.io",
-        "https://my.home-assistant.io",
-    ]
+    assert mock_setup.mock_calls[0][1][1] == ["https://cast.home-assistant.io"]
 
 
 async def test_storing_config(hass, aiohttp_client, aiohttp_unused_port):