diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_consume.c b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_consume.c
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_consume.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_consume.c
@@ -2621,7 +2621,7 @@
 	bcopy(buf->dtbd_data, ndp, buf->dtbd_oldest);
 
 	dt_free(dtp, buf->dtbd_data);
-	buf->dtbd_oldest = 0;
+	buf->dtbd_oldest = misalign;
 	buf->dtbd_data = newdata;
 	buf->dtbd_size += misalign;