diff --git a/bin/dig/dig.c b/bin/dig/dig.c
index 314b41eb97..43907909c8 100644
--- a/bin/dig/dig.c
+++ b/bin/dig/dig.c
@@ -68,7 +68,8 @@ static isc_boolean_t short_form = ISC_FALSE, printcmd = ISC_TRUE,
 	ip6_int = ISC_FALSE, plusquest = ISC_FALSE, pluscomm = ISC_FALSE,
 	multiline = ISC_FALSE, nottl = ISC_FALSE, noclass = ISC_FALSE,
 	onesoa = ISC_FALSE, rrcomments = ISC_FALSE, use_usec = ISC_FALSE,
-	nocrypto = ISC_FALSE, ttlunits = ISC_FALSE;
+	nocrypto = ISC_FALSE, ttlunits = ISC_FALSE, ipv4only = ISC_FALSE,
+	ipv6only = ISC_FALSE;
 static isc_uint32_t splitwidth = 0xffffffff;
 
 /*% opcode text */
@@ -1715,11 +1716,22 @@ preparse_args(int argc, char **argv) {
 			continue;
 		option = &rv[0][1];
 		while (strpbrk(option, single_dash_opts) == &option[0]) {
-			if (option[0] == 'm') {
+			switch (option[0]) {
+			case 'm':
 				memdebugging = ISC_TRUE;
 				isc_mem_debugging = ISC_MEM_DEBUGTRACE |
 					ISC_MEM_DEBUGRECORD;
-				return;
+				break;
+			case '4':
+				if (ipv6only)
+					fatal("only one of -4 and -6 allowed");
+				ipv4only = ISC_TRUE;
+				break;
+			case '6':
+				if (ipv4only)
+					fatal("only one of -4 and -6 allowed");
+				ipv6only = ISC_TRUE;
+				break;
 			}
 			option = &option[1];
 		}
@@ -2081,12 +2093,12 @@ main(int argc, char **argv) {
 	ISC_LIST_INIT(search_list);
 
 	debug("main()");
-	preparse_args(argc, argv);
 	progname = argv[0];
+	preparse_args(argc, argv);
 	result = isc_app_start();
 	check_result(result, "isc_app_start");
 	setup_libs();
-	setup_system();
+	setup_system(ipv4only, ipv6only);
 	parse_args(ISC_FALSE, ISC_FALSE, argc, argv);
 	if (keyfile[0] != 0)
 		setup_file_key();
diff --git a/bin/dig/dighost.c b/bin/dig/dighost.c
index 36441f0c2d..28ac5ece3e 100644
--- a/bin/dig/dighost.c
+++ b/bin/dig/dighost.c
@@ -1339,7 +1339,7 @@ create_search_list(lwres_conf_t *confdata) {
  * settings.
  */
 void
-setup_system(void) {
+setup_system(isc_boolean_t ipv4only, isc_boolean_t ipv6only) {
 	dig_searchlist_t *domain = NULL;
 	lwres_result_t lwresult;
 	unsigned int lwresflags;
@@ -1347,6 +1347,24 @@ setup_system(void) {
 
 	debug("setup_system()");
 
+	if (ipv4only) {
+		if (have_ipv4) {
+			isc_net_disableipv6();
+			have_ipv6 = ISC_FALSE;
+		} else {
+			fatal("can't find IPv4 networking");
+		}
+	}
+
+	if (ipv6only) {
+		if (have_ipv6) {
+			isc_net_disableipv4();
+			have_ipv4 = ISC_FALSE;
+		} else {
+			fatal("can't find IPv6 networking");
+		}
+	}
+
 	lwresflags = LWRES_CONTEXT_SERVERMODE;
 	if (have_ipv4)
 		lwresflags |= LWRES_CONTEXT_USEIPV4;
diff --git a/bin/dig/host.c b/bin/dig/host.c
index aa8685fa2c..8f30f6740a 100644
--- a/bin/dig/host.c
+++ b/bin/dig/host.c
@@ -59,6 +59,7 @@ static int seen_error = -1;
 static isc_boolean_t list_addresses = ISC_TRUE;
 static dns_rdatatype_t list_type = dns_rdatatype_a;
 static isc_boolean_t printed_server = ISC_FALSE;
+static isc_boolean_t ipv4only = ISC_FALSE, ipv6only = ISC_FALSE;
 
 static const char *opcodetext[] = {
 	"QUERY",
@@ -628,8 +629,16 @@ pre_parse_args(int argc, char **argv) {
 				isc_mem_debugging |= ISC_MEM_DEBUGUSAGE;
 			break;
 
-		case '4': break;
-		case '6': break;
+		case '4':
+			if (ipv6only)
+				fatal("only one of -4 and -6 allowed");
+			ipv4only = ISC_TRUE;
+			break;
+		case '6':
+			if (ipv4only)
+				fatal("only one of -4 and -6 allowed");
+			ipv6only = ISC_TRUE;
+			break;
 		case 'a': break;
 		case 'c': break;
 		case 'd': break;
@@ -824,18 +833,10 @@ parse_args(isc_boolean_t is_batchfile, int argc, char **argv) {
 			/* Handled by pre_parse_args(). */
 			break;
 		case '4':
-			if (have_ipv4) {
-				isc_net_disableipv6();
-				have_ipv6 = ISC_FALSE;
-			} else
-				fatal("can't find IPv4 networking");
+			/* Handled by pre_parse_args(). */
 			break;
 		case '6':
-			if (have_ipv6) {
-				isc_net_disableipv4();
-				have_ipv4 = ISC_FALSE;
-			} else
-				fatal("can't find IPv6 networking");
+			/* Handled by pre_parse_args(). */
 			break;
 		case 's':
 			lookup->servfail_stops = ISC_TRUE;
@@ -895,7 +896,7 @@ main(int argc, char **argv) {
 	result = isc_app_start();
 	check_result(result, "isc_app_start");
 	setup_libs();
-	setup_system();
+	setup_system(ipv4only, ipv6only);
 	parse_args(ISC_FALSE, argc, argv);
 	if (keyfile[0] != 0)
 		setup_file_key();
diff --git a/bin/dig/include/dig/dig.h b/bin/dig/include/dig/dig.h
index a2984a5027..478f8377ce 100644
--- a/bin/dig/include/dig/dig.h
+++ b/bin/dig/include/dig/dig.h
@@ -345,7 +345,7 @@ void
 setup_libs(void);
 
 void
-setup_system(void);
+setup_system(isc_boolean_t ipv4only, isc_boolean_t ipv6only);
 
 isc_result_t
 parse_uint(isc_uint32_t *uip, const char *value, isc_uint32_t max,
diff --git a/bin/dig/nslookup.c b/bin/dig/nslookup.c
index 0d364becc2..fcca7f8eba 100644
--- a/bin/dig/nslookup.c
+++ b/bin/dig/nslookup.c
@@ -908,7 +908,7 @@ main(int argc, char **argv) {
 	setup_libs();
 	progname = argv[0];
 
-	setup_system();
+	setup_system(ISC_FALSE, ISC_FALSE);
 	parse_args(argc, argv);
 	if (keyfile[0] != 0)
 		setup_file_key();