diff --git a/lib/dns.c b/lib/dns.c
index bc207cf9..07267e0c 100644
--- a/lib/dns.c
+++ b/lib/dns.c
@@ -3403,27 +3403,33 @@ size_t dns_txt_print(void *dst_, size_t lim, struct dns_txt *txt) {
 } /* dns_txt_print() */
 
 
+typedef int    (*dns_rrtype_parse_fn)(union dns_any *, struct dns_rr *, struct dns_packet *);
+typedef int    (*dns_rrtype_push_fn)(struct dns_packet *, union dns_any *);
+typedef int    (*dns_rrtype_cmp_fn)(const union dns_any *, const union dns_any *);
+typedef size_t (*dns_rrtype_print_fn)(void *, size_t, union dns_any *);
+typedef size_t (*dns_rrtype_cname_fn)(void *, size_t, union dns_any *);
+
 static const struct {
 	enum dns_type type;
 	const char *name;
-	int (*parse)();
-	int (*push)();
-	int (*cmp)();
-	size_t (*print)();
-	size_t (*cname)();
+	dns_rrtype_parse_fn parse;
+	dns_rrtype_push_fn push;
+	dns_rrtype_cmp_fn cmp;
+	dns_rrtype_print_fn print;
+	dns_rrtype_cname_fn cname;
 } dns_rrtypes[]	= {
-	{ DNS_T_A,      "A",      &dns_a_parse,      &dns_a_push,      &dns_a_cmp,      &dns_a_print,      0                },
-	{ DNS_T_AAAA,   "AAAA",   &dns_aaaa_parse,   &dns_aaaa_push,   &dns_aaaa_cmp,   &dns_aaaa_print,   0                },
-	{ DNS_T_MX,     "MX",     &dns_mx_parse,     &dns_mx_push,     &dns_mx_cmp,     &dns_mx_print,     &dns_mx_cname    },
-	{ DNS_T_NS,     "NS",     &dns_ns_parse,     &dns_ns_push,     &dns_ns_cmp,     &dns_ns_print,     &dns_ns_cname    },
-	{ DNS_T_CNAME,  "CNAME",  &dns_cname_parse,  &dns_cname_push,  &dns_cname_cmp,  &dns_cname_print,  &dns_cname_cname },
-	{ DNS_T_SOA,    "SOA",    &dns_soa_parse,    &dns_soa_push,    &dns_soa_cmp,    &dns_soa_print,    0                },
-	{ DNS_T_SRV,    "SRV",    &dns_srv_parse,    &dns_srv_push,    &dns_srv_cmp,    &dns_srv_print,    &dns_srv_cname   },
-	{ DNS_T_OPT,    "OPT",    &dns_opt_parse,    &dns_opt_push,    &dns_opt_cmp,    &dns_opt_print,    0                },
-	{ DNS_T_PTR,    "PTR",    &dns_ptr_parse,    &dns_ptr_push,    &dns_ptr_cmp,    &dns_ptr_print,    &dns_ptr_cname   },
-	{ DNS_T_TXT,    "TXT",    &dns_txt_parse,    &dns_txt_push,    &dns_txt_cmp,    &dns_txt_print,    0                },
-	{ DNS_T_SPF,    "SPF",    &dns_txt_parse,    &dns_txt_push,    &dns_txt_cmp,    &dns_txt_print,    0                },
-	{ DNS_T_SSHFP,  "SSHFP",  &dns_sshfp_parse,  &dns_sshfp_push,  &dns_sshfp_cmp,  &dns_sshfp_print,  0                },
+	{ DNS_T_A,      "A",      (dns_rrtype_parse_fn)&dns_a_parse,      (dns_rrtype_push_fn)&dns_a_push,      (dns_rrtype_cmp_fn)&dns_a_cmp,      (dns_rrtype_print_fn)&dns_a_print,      0                       },
+	{ DNS_T_AAAA,   "AAAA",   (dns_rrtype_parse_fn)&dns_aaaa_parse,   (dns_rrtype_push_fn)&dns_aaaa_push,   (dns_rrtype_cmp_fn)&dns_aaaa_cmp,   (dns_rrtype_print_fn)&dns_aaaa_print,   0                       },
+	{ DNS_T_MX,     "MX",     (dns_rrtype_parse_fn)&dns_mx_parse,     (dns_rrtype_push_fn)&dns_mx_push,     (dns_rrtype_cmp_fn)&dns_mx_cmp,     (dns_rrtype_print_fn)&dns_mx_print,     (dns_rrtype_cname_fn)&dns_mx_cname     },
+	{ DNS_T_NS,     "NS",     (dns_rrtype_parse_fn)&dns_ns_parse,     (dns_rrtype_push_fn)&dns_ns_push,     (dns_rrtype_cmp_fn)&dns_ns_cmp,     (dns_rrtype_print_fn)&dns_ns_print,     (dns_rrtype_cname_fn)&dns_ns_cname     },
+	{ DNS_T_CNAME,  "CNAME",  (dns_rrtype_parse_fn)&dns_cname_parse,  (dns_rrtype_push_fn)&dns_cname_push,  (dns_rrtype_cmp_fn)&dns_cname_cmp,  (dns_rrtype_print_fn)&dns_cname_print,  (dns_rrtype_cname_fn)&dns_cname_cname  },
+	{ DNS_T_SOA,    "SOA",    (dns_rrtype_parse_fn)&dns_soa_parse,    (dns_rrtype_push_fn)&dns_soa_push,    (dns_rrtype_cmp_fn)&dns_soa_cmp,    (dns_rrtype_print_fn)&dns_soa_print,    0                       },
+	{ DNS_T_SRV,    "SRV",    (dns_rrtype_parse_fn)&dns_srv_parse,    (dns_rrtype_push_fn)&dns_srv_push,    (dns_rrtype_cmp_fn)&dns_srv_cmp,    (dns_rrtype_print_fn)&dns_srv_print,    (dns_rrtype_cname_fn)&dns_srv_cname   },
+	{ DNS_T_OPT,    "OPT",    (dns_rrtype_parse_fn)&dns_opt_parse,    (dns_rrtype_push_fn)&dns_opt_push,    (dns_rrtype_cmp_fn)&dns_opt_cmp,    (dns_rrtype_print_fn)&dns_opt_print,    0                       },
+	{ DNS_T_PTR,    "PTR",    (dns_rrtype_parse_fn)&dns_ptr_parse,    (dns_rrtype_push_fn)&dns_ptr_push,    (dns_rrtype_cmp_fn)&dns_ptr_cmp,    (dns_rrtype_print_fn)&dns_ptr_print,    (dns_rrtype_cname_fn)&dns_ptr_cname   },
+	{ DNS_T_TXT,    "TXT",    (dns_rrtype_parse_fn)&dns_txt_parse,    (dns_rrtype_push_fn)&dns_txt_push,    (dns_rrtype_cmp_fn)&dns_txt_cmp,    (dns_rrtype_print_fn)&dns_txt_print,    0                       },
+	{ DNS_T_SPF,    "SPF",    (dns_rrtype_parse_fn)&dns_txt_parse,    (dns_rrtype_push_fn)&dns_txt_push,    (dns_rrtype_cmp_fn)&dns_txt_cmp,    (dns_rrtype_print_fn)&dns_txt_print,    0                       },
+	{ DNS_T_SSHFP,  "SSHFP",  (dns_rrtype_parse_fn)&dns_sshfp_parse,  (dns_rrtype_push_fn)&dns_sshfp_push,  (dns_rrtype_cmp_fn)&dns_sshfp_cmp,  (dns_rrtype_print_fn)&dns_sshfp_print,  0                       },
 }; /* dns_rrtypes[] */
 
 
diff --git a/lib/dns.h b/lib/dns.h
index 2949cb33..1da0d399 100644
--- a/lib/dns.h
+++ b/lib/dns.h
@@ -508,7 +508,7 @@ struct dns_rr_i {
 
 	int follow;
 
-	int (*sort)();
+	int (*sort)(struct dns_rr *, struct dns_rr *, struct dns_rr_i *, struct dns_packet *);
 	unsigned args[2];
 
 	struct {