diff --git a/usr.sbin/route6d/route6d.c b/usr.sbin/route6d/route6d.c
index 3c3d9d30f8c..91c1d372ed9 100644
--- a/usr.sbin/route6d/route6d.c
+++ b/usr.sbin/route6d/route6d.c
@@ -2598,8 +2598,10 @@ krtread(int again)
 			sleep(1);
 		retry++;
 		errmsg = NULL;
-		if (buf)
+		if (buf) {
 			free(buf);
+			buf = NULL;
+		}
 		if (sysctl(mib, 6, NULL, &msize, NULL, 0) < 0) {
 			errmsg = "sysctl estimate";
 			continue;