diff --git a/homeassistant/helpers/config_validation.py b/homeassistant/helpers/config_validation.py
index de9fa2a4169..3a2fb6c70e4 100644
--- a/homeassistant/helpers/config_validation.py
+++ b/homeassistant/helpers/config_validation.py
@@ -120,7 +120,7 @@ def path(value: Any) -> str:
 
 # Adapted from:
 # https://github.com/alecthomas/voluptuous/issues/115#issuecomment-144464666
-def has_at_least_one_key(*keys: str) -> Callable:
+def has_at_least_one_key(*keys: Any) -> Callable[[dict], dict]:
     """Validate that at least one key exists."""
 
     def validate(obj: dict) -> dict:
@@ -131,12 +131,13 @@ def has_at_least_one_key(*keys: str) -> Callable:
         for k in obj:
             if k in keys:
                 return obj
-        raise vol.Invalid("must contain at least one of {}.".format(", ".join(keys)))
+        expected = ", ".join(str(k) for k in keys)
+        raise vol.Invalid(f"must contain at least one of {expected}.")
 
     return validate
 
 
-def has_at_most_one_key(*keys: str) -> Callable[[dict], dict]:
+def has_at_most_one_key(*keys: Any) -> Callable[[dict], dict]:
     """Validate that zero keys exist or one key exists."""
 
     def validate(obj: dict) -> dict:
@@ -145,7 +146,8 @@ def has_at_most_one_key(*keys: str) -> Callable[[dict], dict]:
             raise vol.Invalid("expected dictionary")
 
         if len(set(keys) & set(obj)) > 1:
-            raise vol.Invalid("must contain at most one of {}.".format(", ".join(keys)))
+            expected = ", ".join(str(k) for k in keys)
+            raise vol.Invalid(f"must contain at most one of {expected}.")
         return obj
 
     return validate
diff --git a/tests/helpers/test_config_validation.py b/tests/helpers/test_config_validation.py
index 79b558e5083..cf832dfde50 100644
--- a/tests/helpers/test_config_validation.py
+++ b/tests/helpers/test_config_validation.py
@@ -388,6 +388,34 @@ def test_service_schema():
         cv.SERVICE_SCHEMA(value)
 
 
+def test_entity_service_schema():
+    """Test make_entity_service_schema validation."""
+    schema = cv.make_entity_service_schema(
+        {vol.Required("required"): cv.positive_int, vol.Optional("optional"): cv.string}
+    )
+
+    options = (
+        {},
+        None,
+        {"entity_id": "light.kitchen"},
+        {"optional": "value", "entity_id": "light.kitchen"},
+        {"required": 1},
+        {"required": 2, "area_id": "kitchen", "foo": "bar"},
+        {"required": "str", "area_id": "kitchen"},
+    )
+    for value in options:
+        with pytest.raises(vol.MultipleInvalid):
+            cv.SERVICE_SCHEMA(value)
+
+    options = (
+        {"required": 1, "entity_id": "light.kitchen"},
+        {"required": 2, "optional": "value", "device_id": "a_device"},
+        {"required": 3, "area_id": "kitchen"},
+    )
+    for value in options:
+        schema(value)
+
+
 def test_slug():
     """Test slug validation."""
     schema = vol.Schema(cv.slug)
@@ -912,7 +940,7 @@ def test_has_at_most_one_key():
         with pytest.raises(vol.MultipleInvalid):
             schema(value)
 
-    for value in ({}, {"beer": None}, {"soda": None}):
+    for value in ({}, {"beer": None}, {"soda": None}, {vol.Optional("soda"): None}):
         schema(value)
 
 
@@ -924,7 +952,7 @@ def test_has_at_least_one_key():
         with pytest.raises(vol.MultipleInvalid):
             schema(value)
 
-    for value in ({"beer": None}, {"soda": None}):
+    for value in ({"beer": None}, {"soda": None}, {vol.Required("soda"): None}):
         schema(value)