diff --git a/lib/dns/tests/rdata_test.c b/lib/dns/tests/rdata_test.c
index 2a8e5dd4c7..95ef9a36bb 100644
--- a/lib/dns/tests/rdata_test.c
+++ b/lib/dns/tests/rdata_test.c
@@ -1647,6 +1647,10 @@ zonemd(void **state) {
 		TEXT_INVALID("2019020700 0 0 "),
 		TEXT_INVALID("2019020700 1 0 DEADBEEF"),
 		TEXT_VALID("2019020700 2 0 DEADBEEF"),
+		TEXT_VALID("2019020700 255 0 DEADBEEF"),
+		TEXT_INVALID("2019020700 256 0 DEADBEEF"),
+		TEXT_VALID("2019020700 2 255 DEADBEEF"),
+		TEXT_INVALID("2019020700 2 256 DEADBEEF"),
 		TEXT_VALID("2019020700 1 0 7162D2BB75C047A53DE98767C9192BEB"
 					  "14DB01E7E2267135DAF0230A 19BA4A31"
 					  "6AF6BF64AA5C7BAE24B2992850300509"),