diff --git a/src/InterruptHandler.cpp b/src/InterruptHandler.cpp
index 096a27a..31968c4 100644
--- a/src/InterruptHandler.cpp
+++ b/src/InterruptHandler.cpp
@@ -43,7 +43,7 @@ void InterruptHandler_Init(void)
 
 /**
  * Called every ISR_TIME_US (10 ms).
- * Kept minimal: advance tDecis and wake beepTask via semaphore.
+ * Kept minimal: advance tDecis and wake beepTask via task notification.
  */
 static IRAM_ATTR void timerIsr(void)
 {
@@ -54,7 +54,7 @@ static IRAM_ATTR void timerIsr(void)
         tDecis++;
     }
     BaseType_t woken = pdFALSE;
-    xSemaphoreGiveFromISR(beepSemaphore, &woken);
+    vTaskNotifyGiveFromISR(beepTaskHandle, &woken);
     portYIELD_FROM_ISR(woken);
 }