diff --git a/drivers/can/can.c b/drivers/can/can.c
index d48f852c21..b7e6c3bd5d 100644
--- a/drivers/can/can.c
+++ b/drivers/can/can.c
@@ -389,6 +389,7 @@ static FAR struct can_reader_s *init_can_reader(FAR struct file *filep)
   reader->fifo.rx_tail  = 0;
 
   nxsem_init(&reader->fifo.rx_sem, 0, 1);
+  nxsem_set_protocol(&reader->fifo.rx_sem, SEM_PRIO_NONE);
   filep->f_priv = reader;
 
   return reader;
@@ -1200,6 +1201,7 @@ int can_register(FAR const char *path, FAR struct can_dev_s *dev)
   /* Initialize semaphores */
 
   nxsem_init(&dev->cd_xmit.tx_sem, 0, 1);
+  nxsem_set_protocol(&dev->cd_xmit.tx_sem, SEM_PRIO_NONE);
   nxsem_init(&dev->cd_closesem,    0, 1);
   nxsem_init(&dev->cd_pollsem,     0, 1);