diff --git a/src/mainboard/google/glados/acpi/ec.asl b/src/mainboard/google/glados/acpi/ec.asl
index d69ebe2d01..6546a756dc 100644
--- a/src/mainboard/google/glados/acpi/ec.asl
+++ b/src/mainboard/google/glados/acpi/ec.asl
@@ -21,6 +21,9 @@
 #include "../ec.h"
 #include "../gpio.h"
 
+/* Enable EC backed ALS device in ACPI */
+#define EC_ENABLE_ALS_DEVICE
+
 /* Enable EC backed Keyboard Backlight in ACPI */
 #define EC_ENABLE_KEYBOARD_BACKLIGHT