diff --git a/drivers/ioexpander/pcf8574.c b/drivers/ioexpander/pcf8574.c
index e6bfdd358a..8fca41c7a4 100644
--- a/drivers/ioexpander/pcf8574.c
+++ b/drivers/ioexpander/pcf8574.c
@@ -984,7 +984,7 @@ static void pcf8574_irqworker(void *arg)
 
   sched_lock();
   ret = wd_start(priv->wdog, PCF8574_POLLDELAY,
-                 (wdentry_t)pcf8574_poll_expiry,
+                 pcf8574_poll_expiry,
                  1, (wdparm_t)priv);
   if (ret < 0)
     {
@@ -1155,7 +1155,7 @@ FAR struct ioexpander_dev_s *pcf8574_initialize(FAR struct i2c_master_s *i2c,
   DEBUGASSERT(priv->wdog != NULL);
 
   ret = wd_start(priv->wdog, PCF8574_POLLDELAY,
-                 (wdentry_t)pcf8574_poll_expiry,
+                 pcf8574_poll_expiry,
                  1, (wdparm_t)priv);
   if (ret < 0)
     {
diff --git a/drivers/ioexpander/tca64xx.c b/drivers/ioexpander/tca64xx.c
index 9f359272e9..87d058a0ac 100644
--- a/drivers/ioexpander/tca64xx.c
+++ b/drivers/ioexpander/tca64xx.c
@@ -1257,7 +1257,7 @@ errout_with_restart:
   /* Re-start the poll timer */
 
   sched_lock();
-  ret = wd_start(priv->wdog, TCA64XX_POLLDELAY, (wdentry_t)tca64_poll_expiry,
+  ret = wd_start(priv->wdog, TCA64XX_POLLDELAY, tca64_poll_expiry,
                  1, (wdparm_t)priv);
   if (ret < 0)
     {
@@ -1426,7 +1426,7 @@ FAR struct ioexpander_dev_s *tca64_initialize(FAR struct i2c_master_s *i2c,
   priv->wdog    = wd_create();
   DEBUGASSERT(priv->wdog != NULL);
 
-  ret = wd_start(priv->wdog, TCA64XX_POLLDELAY, (wdentry_t)tca64_poll_expiry,
+  ret = wd_start(priv->wdog, TCA64XX_POLLDELAY, tca64_poll_expiry,
                  1, (wdparm_t)priv);
   if (ret < 0)
     {