diff --git a/homeassistant/helpers/config_validation.py b/homeassistant/helpers/config_validation.py
index 05701e77a9e..ebfccd22ea8 100644
--- a/homeassistant/helpers/config_validation.py
+++ b/homeassistant/helpers/config_validation.py
@@ -47,6 +47,7 @@ def ensure_list(value):
 
 def entity_id(value):
     """Validate Entity ID."""
+    value = string(value).lower()
     if valid_entity_id(value):
         return value
     raise vol.Invalid('Entity ID {} does not match format <domain>.<object_id>'
@@ -58,10 +59,7 @@ def entity_ids(value):
     if isinstance(value, str):
         value = [ent_id.strip() for ent_id in value.split(',')]
 
-    for ent_id in value:
-        entity_id(ent_id)
-
-    return value
+    return [entity_id(ent_id) for ent_id in value]
 
 
 def icon(value):
diff --git a/tests/helpers/test_config_validation.py b/tests/helpers/test_config_validation.py
index dc7074acffb..3f4789eca4f 100644
--- a/tests/helpers/test_config_validation.py
+++ b/tests/helpers/test_config_validation.py
@@ -70,7 +70,7 @@ def test_entity_id():
     with pytest.raises(vol.MultipleInvalid):
         schema('invalid_entity')
 
-    schema('sensor.light')
+    assert 'sensor.light' == schema('sensor.LIGHT')
 
 
 def test_entity_ids():
@@ -94,7 +94,7 @@ def test_entity_ids():
     ):
         schema(value)
 
-    assert schema('sensor.light, light.kitchen ') == [
+    assert schema('sensor.LIGHT, light.kitchen ') == [
         'sensor.light', 'light.kitchen'
     ]