diff --git a/source/components/simple_alarm.markdown b/source/components/simple_alarm.markdown
index 5e553e27aef..ce5e45aceaa 100644
--- a/source/components/simple_alarm.markdown
+++ b/source/components/simple_alarm.markdown
@@ -13,12 +13,17 @@ The component `simple_alarm` is capable of detecting intruders. It does so by ch
 
 This component depends on the components [device_tracker]({{site_root}}/components/device_tracker.html) and [light]({{site_root}}/components/light.html) being setup.
 
-To set it up, add the following lines to your `configuration.yaml`:
+To set it up, add the following lines to your `configuration.yaml` file:
 
-```
+```yaml
 simple_alarm:
-  # Which light/light group has to flash when a known device comes home
+# Example configuration.yaml entry
   known_light: light.Bowl
-  # Which light/light group has to flash red when light turns on while no one home
   unknown_light: group.living_room
 ```
+
+Configuration variables:
+
+- **known_light** (*Required*): Which light/light group has to flash when a known device comes home.
+- **unknown_light** (*Required*): Which light/light group has to flash red when light turns on while no one home.
+