diff --git a/include/nuttx/spi/spi.h b/include/nuttx/spi/spi.h
index c4757bb975..08b28e2625 100644
--- a/include/nuttx/spi/spi.h
+++ b/include/nuttx/spi/spi.h
@@ -320,7 +320,7 @@
  *
  ****************************************************************************/
 
-#define SPI_SEND(d,wd) ((d)->ops->send(d,(uint16_t)wd))
+#define SPI_SEND(d,wd) ((d)->ops->send(d,(uint16_t)(wd)))
 
 /****************************************************************************
  * Name: SPI_SNDBLOCK