diff --git a/sys/dev/disk/isp/isp_target.c b/sys/dev/disk/isp/isp_target.c
--- a/sys/dev/disk/isp/isp_target.c
+++ b/sys/dev/disk/isp/isp_target.c
@@ -171,7 +171,7 @@
 			 * Check for and do something with commands whose
 			 * IULEN extends past a single queue entry.
 			 */
-			len = at7iop->at_ta_len & 0xfffff;
+			len = at7iop->at_ta_len & 0xfff;
 			if (len > (QENTRY_LEN - 8)) {
 				len -= (QENTRY_LEN - 8);
 				isp_prt(isp, ISP_LOGINFO, "long IU length (%d) ignored", len);