diff --git a/components/freemodbus/modbus/rtu/mbrtu_m.c b/components/freemodbus/modbus/rtu/mbrtu_m.c
index f4c1ef4..07b6d25 100644
--- a/components/freemodbus/modbus/rtu/mbrtu_m.c
+++ b/components/freemodbus/modbus/rtu/mbrtu_m.c
@@ -393,7 +393,7 @@ BOOL MB_PORT_ISR_ATTR xMBMasterRTUTimerExpired(void)
     vMBMasterPortTimersDisable( );
     /* If timer mode is convert delay, the master event then turns EV_MASTER_EXECUTE status. */
     if (xMBMasterGetCurTimerMode() == MB_TMODE_CONVERT_DELAY) {
-        xNeedPoll = xMBMasterPortEventPost( EV_MASTER_EXECUTE );
+        xNeedPoll = xMBMasterPortEventPost(EV_MASTER_EXECUTE);
     }
 
     return xNeedPoll;