diff --git a/homeassistant/components/lock/services.yaml b/homeassistant/components/lock/services.yaml
index b792b8f9896..40a7c3ffe38 100644
--- a/homeassistant/components/lock/services.yaml
+++ b/homeassistant/components/lock/services.yaml
@@ -3,13 +3,19 @@ lock:
 
   fields:
     entity_id:
-      description: Name(s) of lock(s) to lock
+      description: Name of lock to lock
       example: 'lock.front_door'
+    code:
+      description: An optional code to lock the lock with
+      example: 1234
 
 unlock:
   description: Unlock all or specified locks
 
   fields:
     entity_id:
-      description: Name(s) of lock(s) to unlock
+      description: Name of lock to unlock
       example: 'lock.front_door'
+    code:
+      description: An optional code to unlock the lock with
+      example: 1234