diff --git a/ports/espressif/common-hal/alarm/__init__.h b/ports/espressif/common-hal/alarm/__init__.h
index e0086ee61a..65cbf96c87 100644
--- a/ports/espressif/common-hal/alarm/__init__.h
+++ b/ports/espressif/common-hal/alarm/__init__.h
@@ -36,7 +36,9 @@
 #endif
 
 typedef union {
+#if CIRCUITPY_ESPULP
     espulp_ulpalarm_obj_t ulp_alarm;
+#endif
     alarm_pin_pinalarm_obj_t pin_alarm;
     alarm_time_timealarm_obj_t time_alarm;
     alarm_touch_touchalarm_obj_t touch_alarm;