diff --git a/libs/core/dal.d.ts b/libs/core/dal.d.ts
index c8760117..28c105e3 100644
--- a/libs/core/dal.d.ts
+++ b/libs/core/dal.d.ts
@@ -192,7 +192,7 @@ declare const enum DAL {
     MICROBIT_SERIAL_EVT_TX_EMPTY = 2,
     MICROBIT_UART_S_EVT_TX_EMPTY = 3,
     // built/yt/yotta_modules/microbit-dal/inc/drivers/CalliopeRGB.h
-    RGB_LED_MAX_INTENSITY = 255,
+    RGB_LED_MAX_INTENSITY = 40,
     // built/yt/yotta_modules/microbit-dal/inc/drivers/CalliopeSoundMotor.h
     CALLIOPE_SM_DEFAULT_DUTY_M = 50,
     CALLIOPE_SM_DEFAULT_DUTY_S = 100,