diff --git a/drivers/spi/spi-spacemit-k1.c b/drivers/spi/spi-spacemit-k1.c
index 99db429db0b2..215fe66d27b4 100644
--- a/drivers/spi/spi-spacemit-k1.c
+++ b/drivers/spi/spi-spacemit-k1.c
@@ -390,7 +390,7 @@ static int k1_spi_set_speed(struct k1_spi_driver_data *drv_data,
 	 *   ticks_per_word = BITS_PER_BYTE * drv_data->bytes;
 	 * We do the divide last for better accuracy.
 	 */
-	nsec_per_word = NSEC_PER_SEC * BITS_PER_BYTE * drv_data->bytes;
+	nsec_per_word = (u64)NSEC_PER_SEC * BITS_PER_BYTE * drv_data->bytes;
 	nsec_per_word = DIV_ROUND_UP_ULL(nsec_per_word, drv_data->rate);
 
 	/*