diff --git a/homeassistant/components/logbook.py b/homeassistant/components/logbook.py
index d26b3373cb8..98740388cd5 100644
--- a/homeassistant/components/logbook.py
+++ b/homeassistant/components/logbook.py
@@ -9,6 +9,8 @@ import re
 from datetime import timedelta
 from itertools import groupby
 
+import voluptuous as vol
+
 import homeassistant.util.dt as dt_util
 from homeassistant.components import recorder, sun
 from homeassistant.const import (
@@ -18,6 +20,7 @@ from homeassistant.core import DOMAIN as HA_DOMAIN
 from homeassistant.core import State
 from homeassistant.helpers.entity import split_entity_id
 from homeassistant.helpers import template
+import homeassistant.helpers.config_validation as cv
 
 DOMAIN = "logbook"
 DEPENDENCIES = ['recorder', 'http']
@@ -39,6 +42,13 @@ ATTR_MESSAGE = 'message'
 ATTR_DOMAIN = 'domain'
 ATTR_ENTITY_ID = 'entity_id'
 
+LOG_MESSAGE_SCHEMA = vol.Schema({
+    vol.Required(ATTR_NAME): cv.string,
+    vol.Required(ATTR_MESSAGE): cv.string,
+    vol.Optional(ATTR_DOMAIN): cv.slug,
+    vol.Optional(ATTR_ENTITY_ID): cv.entity_id,
+})
+
 
 def log_entry(hass, name, message, domain=None, entity_id=None):
     """Add an entry to the logbook."""
@@ -58,19 +68,17 @@ def setup(hass, config):
     """Listen for download events to download files."""
     def log_message(service):
         """Handle sending notification message service calls."""
-        message = service.data.get(ATTR_MESSAGE)
-        name = service.data.get(ATTR_NAME)
-        domain = service.data.get(ATTR_DOMAIN, None)
-        entity_id = service.data.get(ATTR_ENTITY_ID, None)
-
-        if not message or not name:
-            return
+        message = service.data[ATTR_MESSAGE]
+        name = service.data[ATTR_NAME]
+        domain = service.data.get(ATTR_DOMAIN)
+        entity_id = service.data.get(ATTR_ENTITY_ID)
 
         message = template.render(hass, message)
         log_entry(hass, name, message, domain, entity_id)
 
     hass.http.register_path('GET', URL_LOGBOOK, _handle_get_logbook)
-    hass.services.register(DOMAIN, 'log', log_message)
+    hass.services.register(DOMAIN, 'log', log_message,
+                           schema=LOG_MESSAGE_SCHEMA)
     return True
 
 
diff --git a/tests/components/test_logbook.py b/tests/components/test_logbook.py
index d27865f4402..b7e95ad7eed 100644
--- a/tests/components/test_logbook.py
+++ b/tests/components/test_logbook.py
@@ -37,7 +37,7 @@ class TestComponentHistory(unittest.TestCase):
             logbook.ATTR_NAME: 'Alarm',
             logbook.ATTR_MESSAGE: 'is triggered',
             logbook.ATTR_DOMAIN: 'switch',
-            logbook.ATTR_ENTITY_ID: 'test_switch'
+            logbook.ATTR_ENTITY_ID: 'switch.test_switch'
         }, True)
         self.hass.pool.block_till_done()
 
@@ -48,7 +48,7 @@ class TestComponentHistory(unittest.TestCase):
         self.assertEqual('is triggered', last_call.data.get(
             logbook.ATTR_MESSAGE))
         self.assertEqual('switch', last_call.data.get(logbook.ATTR_DOMAIN))
-        self.assertEqual('test_switch', last_call.data.get(
+        self.assertEqual('switch.test_switch', last_call.data.get(
             logbook.ATTR_ENTITY_ID))
 
     def test_service_call_create_log_book_entry_no_message(self):