diff --git a/homeassistant/loader.py b/homeassistant/loader.py
index 1d8d7e8e98f..84d9cd2a72f 100644
--- a/homeassistant/loader.py
+++ b/homeassistant/loader.py
@@ -576,6 +576,9 @@ async def async_get_integration(hass: HomeAssistant, domain: str) -> Integration
 
 
 async def _async_get_integration(hass: HomeAssistant, domain: str) -> Integration:
+    if "." in domain:
+        raise ValueError(f"Invalid domain {domain}")
+
     # Instead of using resolve_from_root we use the cache of custom
     # components to find the integration.
     if integration := (await async_get_custom_components(hass)).get(domain):
diff --git a/tests/test_loader.py b/tests/test_loader.py
index c51e805f400..2bffee75d1e 100644
--- a/tests/test_loader.py
+++ b/tests/test_loader.py
@@ -540,3 +540,9 @@ async def test_custom_integration_missing(hass, caplog):
 
         with pytest.raises(loader.IntegrationNotFound):
             await loader.async_get_integration(hass, "test1")
+
+
+async def test_validation(hass):
+    """Test we raise if invalid domain passed in."""
+    with pytest.raises(ValueError):
+        await loader.async_get_integration(hass, "some.thing")