diff --git a/examples/CustomerBufferSize/CustomerBufferSize.ino b/examples/CustomerBufferSize/CustomerBufferSize.ino
index 3dc8515..864e456 100644
--- a/examples/CustomerBufferSize/CustomerBufferSize.ino
+++ b/examples/CustomerBufferSize/CustomerBufferSize.ino
@@ -8,6 +8,10 @@
 //#include <hardware/BLEMIDI_ESP32.h>
 //#include <hardware/BLEMIDI_ArduinoBLE.h>
 
+#ifndef LED_BUILTIN
+#define LED_BUILTIN 2
+#endif
+
 BLEMIDI_CREATE_CUSTOM_INSTANCE("Esp32-NimBLE-MIDI", MIDI, CustomBufferSizeSettings);
 
 unsigned long t0 = millis();
@@ -61,4 +65,4 @@ void loop()
 
     MIDI.sendNoteOn (60, 100, 1); // note 60, velocity 100 on channel 1
   }
-}
\ No newline at end of file
+}