diff --git a/sys/bus/smbus/ichiic/ig4_iic.c b/sys/bus/smbus/ichiic/ig4_iic.c
index a706fb5..a7c9a2f 100644
--- a/sys/bus/smbus/ichiic/ig4_iic.c
+++ b/sys/bus/smbus/ichiic/ig4_iic.c
@@ -649,6 +649,7 @@ ig4iic_attach(ig4iic_softc_t *sc)
 	error = bus_setup_intr(sc->dev, sc->intr_res, INTR_MPSAFE,
 			       ig4iic_intr, sc, &sc->intr_handle, &sc->slz);
 	if (error) {
+		lwkt_serialize_exit(&sc->slz);
 		device_printf(sc->dev,
 			      "Unable to setup irq: error %d\n", error);
 		goto done;