diff --git a/drivers/serial/uart_bth5.c b/drivers/serial/uart_bth5.c
index 1b7385edce4..9e88eed6b6a 100644
--- a/drivers/serial/uart_bth5.c
+++ b/drivers/serial/uart_bth5.c
@@ -73,7 +73,6 @@
 #define H5_SET_TYPE(hdr, type)  ((hdr)[1] |= (type))
 #define H5_SET_LEN(hdr, len)    (((hdr)[1] |= ((len)&0x0f) << 4), ((hdr)[2] |= (len) >> 4))
 
-#define H5_ACK_TIMEOUT MSEC2TICK(250)  /* 250ms */
 #define H5_RTX_TIMEOUT MSEC2TICK(150)  /* 150ms */
 
 union bt_hdr_u
@@ -466,11 +465,7 @@ h5_recv_handle(FAR struct uart_bth5_s *dev)
   if (H5_HDR_RELIABLE(hdr))
     {
       dev->txack = (dev->txack + 1) & 0x07;
-      if (work_available(&dev->ackworker))
-        {
-          work_queue(HPWORK, &dev->ackworker, h5_ack_work, dev,
-                     H5_ACK_TIMEOUT);
-        }
+      h5_ack_work(dev);
     }
 
   dev->rxack = H5_HDR_ACK(hdr);
@@ -563,7 +558,7 @@ h5_rx_header(FAR struct uart_bth5_s *dev, uint8_t c)
 
   if (H5_HDR_RELIABLE(hdr) && H5_HDR_SEQ(hdr) != dev->txack)
     {
-      work_queue(HPWORK, &dev->ackworker, h5_ack_work, dev, 0);
+      h5_ack_work(dev);
       h5_rx_reset(dev);
       return -EINVAL;
     }
@@ -1114,7 +1109,7 @@ uart_bth5_write(FAR struct file *filep, FAR const char *buffer,
 
       if (h5_unack_size(&dev->unackpool) > dev->txwin)
         {
-          work_queue(HPWORK, &dev->ackworker, h5_ack_work, dev, 0);
+          h5_ack_work(dev);
           if (filep->f_oflags & O_NONBLOCK)
             {
               ret = -EAGAIN;