diff --git a/flight/PiOS/Common/pios_com.c b/flight/PiOS/Common/pios_com.c
index 9f325fa1f..739329f15 100644
--- a/flight/PiOS/Common/pios_com.c
+++ b/flight/PiOS/Common/pios_com.c
@@ -161,7 +161,7 @@ out_fail:
 static void PIOS_COM_UnblockRx(struct pios_com_dev * com_dev, bool * need_yield)
 {
 #if defined(PIOS_INCLUDE_FREERTOS)
-	static signed portBASE_TYPE xHigherPriorityTaskWoken;
+	static signed portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
 	xSemaphoreGiveFromISR(com_dev->rx_sem, &xHigherPriorityTaskWoken);
 
 	if (xHigherPriorityTaskWoken != pdFALSE) {
@@ -177,7 +177,7 @@ static void PIOS_COM_UnblockRx(struct pios_com_dev * com_dev, bool * need_yield)
 static void PIOS_COM_UnblockTx(struct pios_com_dev * com_dev, bool * need_yield)
 {
 #if defined(PIOS_INCLUDE_FREERTOS)
-	static signed portBASE_TYPE xHigherPriorityTaskWoken;
+	static signed portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
 	xSemaphoreGiveFromISR(com_dev->tx_sem, &xHigherPriorityTaskWoken);
 
 	if (xHigherPriorityTaskWoken != pdFALSE) {