diff --git a/sys/dev/isp/isp.c b/sys/dev/isp/isp.c
index 586b75b044d0..dfa8d8c3884a 100644
--- a/sys/dev/isp/isp.c
+++ b/sys/dev/isp/isp.c
@@ -2039,8 +2039,8 @@ isp_control(isp, ctl, arg)
 			bus = *((int *) arg);
 			mbs.param[2] = bus;
 		} else {
-			/* Unparameterized. */
 			mbs.param[1] = 10;
+			mbs.param[2] = 0;
 			bus = 0;
 		}
 		isp->isp_sendmarker = 1 << bus;