diff --git a/test/dm/spi.c b/test/dm/spi.c
index 249a9238fedc..a89ba06274fc 100644
--- a/test/dm/spi.c
+++ b/test/dm/spi.c
@@ -170,6 +170,22 @@ static int dm_test_spi_claim_bus(struct unit_test_state *uts)
 }
 DM_TEST(dm_test_spi_claim_bus, UTF_SCAN_PDATA | UTF_SCAN_FDT);
 
+static int dm_test_spi_set_wordlen(struct unit_test_state *uts)
+{
+	struct spi_slave *slave;
+	struct udevice *bus;
+	const int busnum = 0, cs = 0;
+
+	ut_assertok(spi_get_bus_and_cs(busnum, cs, &bus, &slave));
+	ut_assertok(spi_set_wordlen(slave, 8));
+	ut_asserteq(8, sandbox_spi_get_wordlen(slave->dev));
+	ut_assertok(spi_set_wordlen(slave, 9));
+	ut_asserteq(9, sandbox_spi_get_wordlen(slave->dev));
+
+	return 0;
+}
+DM_TEST(dm_test_spi_set_wordlen, UTF_SCAN_PDATA | UTF_SCAN_FDT);
+
 /* Test that sandbox SPI works correctly */
 static int dm_test_spi_xfer(struct unit_test_state *uts)
 {