diff --git a/bin/tools/dnstap-read.c b/bin/tools/dnstap-read.c
index c9d30ab7df..756b22b38b 100644
--- a/bin/tools/dnstap-read.c
+++ b/bin/tools/dnstap-read.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2017  Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (C) 2015-2018  Internet Systems Consortium, Inc. ("ISC")
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -223,7 +223,7 @@ print_yaml(dns_dtdata_t *dt) {
 	}
 
 	if (dt->msgdata.base != NULL) {
-		printf("  message_size: %zdb\n", (size_t) dt->msgdata.length);
+		printf("  message_size: %zub\n", (size_t) dt->msgdata.length);
 	} else
 		printf("  message_size: 0b\n");
 
diff --git a/util/copyrights b/util/copyrights
index 67c4e70648..43189359ac 100644
--- a/util/copyrights
+++ b/util/copyrights
@@ -2610,7 +2610,7 @@
 ./bin/tools/arpaname.docbook			SGML	2009,2014,2015,2016
 ./bin/tools/arpaname.html			HTML	DOCBOOK
 ./bin/tools/dnstap-read.1			MAN	DOCBOOK
-./bin/tools/dnstap-read.c			C	2015,2016,2017
+./bin/tools/dnstap-read.c			C	2015,2016,2017,2018
 ./bin/tools/dnstap-read.docbook			SGML	2015,2016,2017
 ./bin/tools/dnstap-read.html			HTML	DOCBOOK
 ./bin/tools/genrandom.8				MAN	DOCBOOK