diff --git a/lib/dns/openssleddsa_link.c b/lib/dns/openssleddsa_link.c
index d19af94395..86b771f2f3 100644
--- a/lib/dns/openssleddsa_link.c
+++ b/lib/dns/openssleddsa_link.c
@@ -570,6 +570,7 @@ openssleddsa_todns(const dst_key_t *key, isc_buffer_t *data) {
 	default:
 		INSIST(0);
 	}
+	return (DST_R_OPENSSLFAILURE);
 }
 
 static isc_result_t
diff --git a/lib/dns/rdata/generic/loc_29.c b/lib/dns/rdata/generic/loc_29.c
index 7af1c18731..388742b836 100644
--- a/lib/dns/rdata/generic/loc_29.c
+++ b/lib/dns/rdata/generic/loc_29.c
@@ -551,7 +551,7 @@ totext_loc(ARGS_TOTEXT) {
 		altitude -= 10000000;
 	}
 
-	snprintf(NULL, 0,
+	snprintf(buf, sizeof(buf),
 		 "%d %d %d.%03d %s %d %d %d.%03d %s %s%lu.%02lum %s %s %s",
 		 d1, m1, s1, fs1, north ? "N" : "S",
 		 d2, m2, s2, fs2, east ? "E" : "W",
diff --git a/lib/dns/rdata/in_1/dhcid_49.c b/lib/dns/rdata/in_1/dhcid_49.c
index 9fce42d473..1f2c30d883 100644
--- a/lib/dns/rdata/in_1/dhcid_49.c
+++ b/lib/dns/rdata/in_1/dhcid_49.c
@@ -36,7 +36,7 @@ static inline isc_result_t
 totext_in_dhcid(ARGS_TOTEXT) {
 	isc_region_t sr, sr2;
 	/* " ; 64000 255 64000" */
-	char buf[5 + 3*5 + 1];
+	char buf[5 + 3*11 + 1];
 
 	REQUIRE(rdata->type == dns_rdatatype_dhcid);
 	REQUIRE(rdata->rdclass == dns_rdataclass_in);
@@ -55,7 +55,7 @@ totext_in_dhcid(ARGS_TOTEXT) {
 	if ((tctx->flags & DNS_STYLEFLAG_MULTILINE) != 0) {
 		RETERR(str_totext(/* ( */ " )", target));
 		if (rdata->length > 2) {
-			snprintf(NULL, 0, " ; %u %u %u",
+			snprintf(buf, sizeof(buf), " ; %u %u %u",
 				 sr2.base[0] * 256U + sr2.base[1],
 				 sr2.base[2], rdata->length - 3U);
 			RETERR(str_totext(buf, target));