diff --git a/homeassistant/components/person/__init__.py b/homeassistant/components/person/__init__.py
index 9cd3e882c48..006929c7345 100644
--- a/homeassistant/components/person/__init__.py
+++ b/homeassistant/components/person/__init__.py
@@ -77,7 +77,11 @@ PERSON_SCHEMA = vol.Schema(
 )
 
 CONFIG_SCHEMA = vol.Schema(
-    {vol.Optional(DOMAIN): vol.All(cv.ensure_list, cv.remove_falsy, [PERSON_SCHEMA])},
+    {
+        vol.Optional(DOMAIN, default=[]): vol.All(
+            cv.ensure_list, cv.remove_falsy, [PERSON_SCHEMA]
+        )
+    },
     extra=vol.ALLOW_EXTRA,
 )
 
diff --git a/homeassistant/config.py b/homeassistant/config.py
index 27aff8ca36b..b1cd49b0852 100644
--- a/homeassistant/config.py
+++ b/homeassistant/config.py
@@ -571,7 +571,9 @@ def _identify_config_schema(module: ModuleType) -> Tuple[Optional[str], Optional
 
     schema = module.CONFIG_SCHEMA.schema[key]  # type: ignore
 
-    if hasattr(key, "default"):
+    if hasattr(key, "default") and not isinstance(
+        key.default, vol.schema_builder.Undefined
+    ):
         default_value = schema(key.default())
 
         if isinstance(default_value, dict):