diff --git a/CHANGES b/CHANGES
index 726e201b06..27848a6f95 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+5947.	[func]		Change dnssec-policy to allow graceful transition from
+			an NSEC only zone to NSEC3. [GL #3486]
+
 5946.	[bug]		Fix statistics channel's handling of multiple HTTP
 			requests in a single connection which have non-empty
 			request bodies. [GL #3463]
diff --git a/bin/dnssec/dnssec-signzone.c b/bin/dnssec/dnssec-signzone.c
index 889ca79ab5..1780a93ae8 100644
--- a/bin/dnssec/dnssec-signzone.c
+++ b/bin/dnssec/dnssec-signzone.c
@@ -3901,7 +3901,7 @@ main(int argc, char *argv[]) {
 		hashlist_init(&hashlist,
 			      dns_db_nodecount(gdb, dns_dbtree_main) * 2,
 			      hash_length);
-		result = dns_nsec_nseconly(gdb, gversion, &answer);
+		result = dns_nsec_nseconly(gdb, gversion, NULL, &answer);
 		if (result == ISC_R_NOTFOUND) {
 			fprintf(stderr,
 				"%s: warning: NSEC3 generation "
diff --git a/bin/tests/system/checkconf/bad-kasp-nsec3-alg.conf b/bin/tests/system/checkconf/bad-kasp-nsec3-alg.conf
new file mode 100644
index 0000000000..ff25ecea38
--- /dev/null
+++ b/bin/tests/system/checkconf/bad-kasp-nsec3-alg.conf
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * 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
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+dnssec-policy "badnsec3alg" {
+	keys {
+		csk lifetime unlimited algorithm rsasha1;
+	};
+	nsec3param iterations 0 optout 0 salt-length 0;
+};
+
+zone "example.net" {
+	type primary;
+	file "example.db";
+	dnssec-policy "badnsec3alg";
+};
diff --git a/bin/tests/system/nsec3/clean.sh b/bin/tests/system/nsec3/clean.sh
index 6383f29bea..d6b11e749b 100644
--- a/bin/tests/system/nsec3/clean.sh
+++ b/bin/tests/system/nsec3/clean.sh
@@ -13,9 +13,10 @@
 
 set -e
 
-rm -f dig.out.* rndc.signing.*
+rm -f dig.out.* rndc.signing.* verify.out.*
 rm -f ns*/named.conf ns*/named.memstats ns*/named.run*
 rm -f ns*/*.jnl ns*/*.jbk ns*/managed-keys.bind
 rm -f ns*/K*.private ns*/K*.key ns*/K*.state
 rm -f ns*/dsset-* ns*/*.db ns*/*.db.signed
-
+rm -f ns*/keygen.out.* ns*/settime.out.*
+rm -f created.key-* *.created unused.key-*
diff --git a/bin/tests/system/nsec3/ns3/named.conf.in b/bin/tests/system/nsec3/ns3/named.conf.in
index 36c217ad3c..c94fa5d679 100644
--- a/bin/tests/system/nsec3/ns3/named.conf.in
+++ b/bin/tests/system/nsec3/ns3/named.conf.in
@@ -18,6 +18,12 @@ dnssec-policy "nsec" {
 	// NSEC will be used;
 };
 
+dnssec-policy "rsasha1" {
+	keys {
+		csk lifetime unlimited algorithm rsasha1;
+	};
+};
+
 dnssec-policy "nsec3" {
 	nsec3param;
 };
@@ -59,6 +65,56 @@ zone "nsec-to-nsec3.kasp" {
 	dnssec-policy "nsec";
 };
 
+/*
+ * This zone starts with NSEC, but will be reconfigured to use NSEC3.
+ * This should work despite the incompatible RSAHSHA1 algorithm,
+ * because the DS is still in hidden state.
+ */
+zone "rsasha1-to-nsec3.kasp" {
+	type primary;
+	file "rsasha1-to-nsec3.kasp.db";
+	inline-signing yes;
+	dnssec-policy "rsasha1";
+};
+
+/*
+ * This zone starts with NSEC, but will be reconfigured to use NSEC3.
+ * This should block because RSASHA1 is not compatible with NSEC3,
+ * and the DS is published.
+ */
+zone "rsasha1-to-nsec3-wait.kasp" {
+	type primary;
+	file "rsasha1-to-nsec3-wait.kasp.db";
+	inline-signing yes;
+	dnssec-policy "rsasha1";
+};
+
+/*
+ * This zone starts with NSEC3, but will be reconfigured to use NSEC with an
+ * NSEC only algorithm. This should work despite the incompatible RSAHSHA1
+ * algorithm, because the DS is still in hidden state.
+ */
+zone "nsec3-to-rsasha1.kasp" {
+	type primary;
+	file "nsec3-to-rsasha1.kasp.db";
+	inline-signing yes;
+	dnssec-policy "nsec3";
+};
+
+/*
+ * This zone starts with NSEC3, but will be reconfigured to use NSEC with an
+ * NSEC only algorithm. This should also be fine because we are allowed
+ * to change to NSEC with any algorithm, then we can also publish the new
+ * DNSKEY and signatures of the RSASHA1 algorithm.
+ */
+zone "nsec3-to-rsasha1-ds.kasp" {
+	type primary;
+	file "nsec3-to-rsasha1-ds.kasp.db";
+	inline-signing yes;
+	dnssec-policy "nsec3";
+};
+
+
 /* These zones use the default NSEC3 settings. */
 zone "nsec3.kasp" {
 	type primary;
diff --git a/bin/tests/system/nsec3/ns3/named2.conf.in b/bin/tests/system/nsec3/ns3/named2.conf.in
index c81cd70049..d9764abcad 100644
--- a/bin/tests/system/nsec3/ns3/named2.conf.in
+++ b/bin/tests/system/nsec3/ns3/named2.conf.in
@@ -18,6 +18,12 @@ dnssec-policy "nsec" {
 	// NSEC will be used;
 };
 
+dnssec-policy "rsasha1" {
+	keys {
+		csk lifetime unlimited algorithm rsasha1;
+	};
+};
+
 dnssec-policy "nsec3" {
 	nsec3param;
 };
@@ -60,6 +66,59 @@ zone "nsec-to-nsec3.kasp" {
 	dnssec-policy "nsec3";
 };
 
+/*
+ * This zone starts with NSEC, but will be reconfigured to use NSEC3.
+ * This should work despite the incompatible RSAHSHA1 algorithm,
+ * because the DS is still in hidden state.
+ */
+zone "rsasha1-to-nsec3.kasp" {
+	type primary;
+	file "rsasha1-to-nsec3.kasp.db";
+	inline-signing yes;
+	//dnssec-policy "rsasha1";
+	dnssec-policy "nsec3";
+};
+
+/*
+ * This zone starts with NSEC, but will be reconfigured to use NSEC3.
+ * This should block because RSASHA1 is not compatible with NSEC3,
+ * and the DS is published.
+ */
+zone "rsasha1-to-nsec3-wait.kasp" {
+	type primary;
+	file "rsasha1-to-nsec3-wait.kasp.db";
+	inline-signing yes;
+	//dnssec-policy "rsasha1";
+	dnssec-policy "nsec3";
+};
+
+/*
+ * This zone starts with NSEC3, but will be reconfigured to use NSEC with an
+ * NSEC only algorithm. This should work despite the incompatible RSAHSHA1
+ * algorithm, because the DS is still in hidden state.
+ */
+zone "nsec3-to-rsasha1.kasp" {
+	type primary;
+	file "nsec3-to-rsasha1.kasp.db";
+	inline-signing yes;
+	//dnssec-policy "nsec3";
+	dnssec-policy "rsasha1";
+};
+
+/*
+ * This zone starts with NSEC3, but will be reconfigured to use NSEC with an
+ * NSEC only algorithm. This should also be fine because we are allowed
+ * to change to NSEC with any algorithm, then we can also publish the new
+ * DNSKEY and signatures of the RSASHA1 algorithm.
+ */
+zone "nsec3-to-rsasha1-ds.kasp" {
+	type primary;
+	file "nsec3-to-rsasha1-ds.kasp.db";
+	inline-signing yes;
+	//dnssec-policy "nsec3";
+	dnssec-policy "rsasha1";
+};
+
 /* These zones use the default NSEC3 settings. */
 zone "nsec3.kasp" {
 	type primary;
diff --git a/bin/tests/system/nsec3/ns3/setup.sh b/bin/tests/system/nsec3/ns3/setup.sh
index cbaf84ce8d..e2478ac3df 100644
--- a/bin/tests/system/nsec3/ns3/setup.sh
+++ b/bin/tests/system/nsec3/ns3/setup.sh
@@ -30,4 +30,29 @@ do
 	setup "${zn}.kasp"
 done
 
+if (cd ..; $SHELL ../testcrypto.sh -q RSASHA1)
+then
+	for zn in rsasha1-to-nsec3 rsasha1-to-nsec3-wait nsec3-to-rsasha1 \
+		  nsec3-to-rsasha1-ds
+	do
+		setup "${zn}.kasp"
+	done
+
+	longago="now-1y"
+	keytimes="-P ${longago} -A ${longago}"
+	O="omnipresent"
+
+	zone="rsasha1-to-nsec3-wait.kasp"
+	CSK=$($KEYGEN -k "rsasha1" -l named.conf $keytimes $zone 2> keygen.out.$zone)
+	echo_i "Created key file $CSK"
+	$SETTIME -s -g $O -k $O $longago -r $O $longago -z $O $longago -d $O $longago "$CSK" > settime.out.$zone 2>&1
+
+	zone="nsec3-to-rsasha1-ds.kasp"
+	CSK=$($KEYGEN -k "default" -l named.conf $keytimes $zone 2> keygen.out.$zone)
+	echo_i "Created key file $CSK"
+	$SETTIME -s -g $O -k $O $longago -r $O $longago -z $O $longago -d $O $longago "$CSK" > settime.out.$zone 2>&1
+else
+	echo_i "skip: skip rsasha1 zones - signing with RSASHA1 not supported"
+fi
+
 cp nsec3-fails-to-load.kasp.db.in nsec3-fails-to-load.kasp.db
diff --git a/bin/tests/system/nsec3/tests.sh b/bin/tests/system/nsec3/tests.sh
index d9c2b83d17..1d9adbc3a2 100644
--- a/bin/tests/system/nsec3/tests.sh
+++ b/bin/tests/system/nsec3/tests.sh
@@ -36,6 +36,8 @@ rndccmd() {
 set_zone_policy() {
 	ZONE=$1
 	POLICY=$2
+	NUM_KEYS=$3
+	DNSKEY_TTL=$4
 }
 # Set expected NSEC3 parameters: flags ($1), iterations ($2), and
 # salt length ($3).
@@ -47,6 +49,49 @@ set_nsec3param() {
 	SALT=""
 }
 
+# Set expected default dnssec-policy keys values.
+set_key_default_values() {
+	key_clear $1
+
+	set_keyrole      $1 "csk"
+	set_keylifetime  $1 "0"
+	set_keyalgorithm $1 "13" "ECDSAP256SHA256" "256"
+	set_keysigning   $1 "yes"
+	set_zonesigning  $1 "yes"
+
+	set_keystate $1 "GOAL"         "omnipresent"
+	set_keystate $1 "STATE_DNSKEY" "rumoured"
+	set_keystate $1 "STATE_KRRSIG" "rumoured"
+	set_keystate $1 "STATE_ZRRSIG" "rumoured"
+	set_keystate $1 "STATE_DS"     "hidden"
+}
+
+# Set expected rsasha1 dnssec-policy keys values.
+set_key_rsasha1_values() {
+	key_clear $1
+
+	set_keyrole      $1 "csk"
+	set_keylifetime  $1 "0"
+	set_keyalgorithm $1 "5" "RSASHA1" "2048"
+	set_keysigning   $1 "yes"
+	set_zonesigning  $1 "yes"
+
+	set_keystate $1 "GOAL"         "omnipresent"
+	set_keystate $1 "STATE_DNSKEY" "rumoured"
+	set_keystate $1 "STATE_KRRSIG" "rumoured"
+	set_keystate $1 "STATE_ZRRSIG" "rumoured"
+	set_keystate $1 "STATE_DS"     "hidden"
+}
+
+# Update the key states.
+set_key_states() {
+	set_keystate $1 "GOAL"         "$2"
+	set_keystate $1 "STATE_DNSKEY" "$3"
+	set_keystate $1 "STATE_KRRSIG" "$4"
+	set_keystate $1 "STATE_ZRRSIG" "$5"
+	set_keystate $1 "STATE_DS"     "$6"
+}
+
 # The apex NSEC3PARAM record indicates that it is signed.
 _wait_for_nsec3param() {
 	dig_with_opts +noquestion "@${SERVER}" "$ZONE" NSEC3PARAM > "dig.out.test$n.wait" || return 1
@@ -67,7 +112,7 @@ _wait_for_nsec() {
 wait_for_zone_is_signed() {
 	n=$((n+1))
 	ret=0
-	echo_i "wait for ${ZONE} to be signed ($n)"
+	echo_i "wait for ${ZONE} to be signed with $1 ($n)"
 
 	if [ "$1" = "nsec3" ]; then
 		retry_quiet 10 _wait_for_nsec3param || log_error "wait for ${ZONE} to be signed failed"
@@ -79,24 +124,45 @@ wait_for_zone_is_signed() {
 	status=$((status+ret))
 }
 
+# Test: check DNSSEC verify
+_check_dnssec_verify() {
+        dig_with_opts @$SERVER "${ZONE}" AXFR > "dig.out.test$n.axfr.$ZONE" || return 1
+        $VERIFY -z -o "$ZONE" "dig.out.test$n.axfr.$ZONE" > "verify.out.test$n.$ZONE" 2>&1 || return 1
+	return 0
+}
+
 # Test: check NSEC in answers
-_check_nsec_nsec3param()
-{
+_check_nsec_nsec3param() {
 	dig_with_opts +noquestion @$SERVER "${ZONE}" NSEC3PARAM > "dig.out.test$n.nsec3param.$ZONE" || return 1
 	grep "NSEC3PARAM" "dig.out.test$n.nsec3param.$ZONE" > /dev/null && return 1
 	return 0
 }
 
-_check_nsec_nxdomain()
-{
+_check_nsec_nxdomain() {
 	dig_with_opts @$SERVER "nosuchname.${ZONE}" > "dig.out.test$n.nxdomain.$ZONE" || return 1
 	grep "${ZONE}.*IN.*NSEC.*NS.*SOA.*RRSIG.*NSEC.*DNSKEY" "dig.out.test$n.nxdomain.$ZONE" > /dev/null || return 1
 	grep "NSEC3" "dig.out.test$n.nxdomain.$ZONE" > /dev/null && return 1
 	return 0
 }
 
-check_nsec()
-{
+check_nsec() {
+	wait_for_zone_is_signed "nsec"
+
+	n=$((n+1))
+	echo_i "check DNSKEY rrset is signed correctly for zone ${ZONE} ($n)"
+	ret=0
+	check_keys
+	retry_quiet 10 _check_apex_dnskey || log_error "bad DNSKEY RRset for zone ${ZONE}"
+	test "$ret" -eq 0 || echo_i "failed"
+	status=$((status+ret))
+
+	n=$((n+1))
+	echo_i "verify DNSSEC for zone ${ZONE} ($n)"
+	ret=0
+	retry_quiet 10 _check_dnssec_verify || log_error "DNSSEC verify failed for zone ${ZONE}"
+	test "$ret" -eq 0 || echo_i "failed"
+	status=$((status+ret))
+
 	n=$((n+1))
 	echo_i "check NSEC3PARAM response for zone ${ZONE} ($n)"
 	ret=0
@@ -113,8 +179,7 @@ check_nsec()
 }
 
 # Test: check NSEC3 parameters in answers
-_check_nsec3_nsec3param()
-{
+_check_nsec3_nsec3param() {
 	dig_with_opts +noquestion @$SERVER "${ZONE}" NSEC3PARAM > "dig.out.test$n.nsec3param.$ZONE" || return 1
 	grep "${ZONE}.*0.*IN.*NSEC3PARAM.*1.*0.*${ITERATIONS}.*${SALT}" "dig.out.test$n.nsec3param.$ZONE" > /dev/null || return 1
 
@@ -124,15 +189,15 @@ _check_nsec3_nsec3param()
 	return 0
 }
 
-_check_nsec3_nxdomain()
-{
+_check_nsec3_nxdomain() {
 	dig_with_opts @$SERVER "nosuchname.${ZONE}" > "dig.out.test$n.nxdomain.$ZONE" || return 1
 	grep ".*\.${ZONE}.*IN.*NSEC3.*1.${FLAGS}.*${ITERATIONS}.*${SALT}" "dig.out.test$n.nxdomain.$ZONE" > /dev/null || return 1
 	return 0
 }
 
-check_nsec3()
-{
+check_nsec3() {
+	wait_for_zone_is_signed "nsec3"
+
 	n=$((n+1))
 	echo_i "check that NSEC3PARAM 1 0 ${ITERATIONS} is published zone ${ZONE} ($n)"
 	ret=0
@@ -146,74 +211,119 @@ check_nsec3()
 	retry_quiet 10 _check_nsec3_nxdomain || log_error "bad NXDOMAIN response for zone ${ZONE}"
 	test "$ret" -eq 0 || echo_i "failed"
 	status=$((status+ret))
+
+	n=$((n+1))
+	echo_i "verify DNSSEC for zone ${ZONE} ($n)"
+	ret=0
+	retry_quiet 10 _check_dnssec_verify || log_error "DNSSEC verify failed for zone ${ZONE}"
+	test "$ret" -eq 0 || echo_i "failed"
+	status=$((status+ret))
 }
 
 start_time="$(TZ=UTC date +%s)"
 status=0
 n=0
 
+key_clear "KEY1"
+key_clear "KEY2"
+key_clear "KEY3"
+key_clear "KEY4"
+
 # Zone: nsec-to-nsec3.kasp.
-set_zone_policy "nsec-to-nsec3.kasp" "nsec"
+set_zone_policy "nsec-to-nsec3.kasp" "nsec" 1 3600
 set_server "ns3" "10.53.0.3"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec
-dnssec_verify
+
+if ($SHELL ../testcrypto.sh -q RSASHA1)
+then
+	# Zone: rsasha1-to-nsec3.kasp.
+	set_zone_policy "rsasha1-to-nsec3.kasp" "rsasha1" 1 3600
+	set_server "ns3" "10.53.0.3"
+	set_key_rsasha1_values "KEY1"
+	echo_i "initial check zone ${ZONE}"
+	check_nsec
+
+	# Zone: rsasha1-to-nsec3-wait.kasp.
+	set_zone_policy "rsasha1-to-nsec3-wait.kasp" "rsasha1" 1 3600
+	set_server "ns3" "10.53.0.3"
+	set_key_rsasha1_values "KEY1"
+	set_key_states "KEY1" "omnipresent" "omnipresent" "omnipresent" "omnipresent" "omnipresent"
+	echo_i "initial check zone ${ZONE}"
+	check_nsec
+
+	# Zone: nsec3-to-rsasha1.kasp.
+	set_zone_policy "nsec3-to-rsasha1.kasp" "nsec3" 1 3600
+	set_server "ns3" "10.53.0.3"
+	set_key_rsasha1_values "KEY1"
+	echo_i "initial check zone ${ZONE}"
+	check_nsec3
+
+	# Zone: nsec3-to-rsasha1-ds.kasp.
+	set_zone_policy "nsec3-to-rsasha1-ds.kasp" "nsec3" 1 3600
+	set_server "ns3" "10.53.0.3"
+	set_key_rsasha1_values "KEY1"
+	set_key_states "KEY1" "omnipresent" "omnipresent" "omnipresent" "omnipresent" "omnipresent"
+	echo_i "initial check zone ${ZONE}"
+	check_nsec3
+fi
 
 # Zone: nsec3.kasp.
-set_zone_policy "nsec3.kasp" "nsec3"
+set_zone_policy "nsec3.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-dynamic.kasp.
-set_zone_policy "nsec3-dynamic.kasp" "nsec3"
+set_zone_policy "nsec3-dynamic.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-change.kasp.
-set_zone_policy "nsec3-change.kasp" "nsec3"
+set_zone_policy "nsec3-change.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-dynamic-change.kasp.
-set_zone_policy "nsec3-dynamic-change.kasp" "nsec3"
+set_zone_policy "nsec3-dynamic-change.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-to-nsec.kasp.
-set_zone_policy "nsec3-to-nsec.kasp" "nsec3"
+set_zone_policy "nsec3-to-nsec.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-to-optout.kasp.
-set_zone_policy "nsec3-to-optout.kasp" "nsec3"
+set_zone_policy "nsec3-to-optout.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-from-optout.kasp.
-set_zone_policy "nsec3-from-optout.kasp" "optout"
+set_zone_policy "nsec3-from-optout.kasp" "optout" 1 3600
 set_nsec3param "1" "0" "0"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-other.kasp.
-set_zone_policy "nsec3-other.kasp" "nsec3-other"
+set_zone_policy "nsec3-other.kasp" "nsec3-other" 1 3600
 set_nsec3param "1" "11" "8"
+set_key_default_values "KEY1"
 echo_i "initial check zone ${ZONE}"
 check_nsec3
-dnssec_verify
 
 # Reconfig named.
 echo_i "reconfig dnssec-policy to trigger nsec3 rollovers"
@@ -221,88 +331,141 @@ copy_setports ns3/named2.conf.in ns3/named.conf
 rndc_reconfig ns3 10.53.0.3
 
 # Zone: nsec-to-nsec3.kasp. (reconfigured)
-set_zone_policy "nsec-to-nsec3.kasp" "nsec3"
+set_zone_policy "nsec-to-nsec3.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} after reconfig"
 check_nsec3
-dnssec_verify
+
+if ($SHELL ../testcrypto.sh -q RSASHA1)
+then
+	# Zone: rsasha1-to-nsec3.kasp.
+	set_zone_policy "rsasha1-to-nsec3.kasp" "nsec3" 2 3600
+	set_server "ns3" "10.53.0.3"
+	set_key_rsasha1_values "KEY1"
+	set_key_states "KEY1" "hidden" "unretentive" "unretentive" "unretentive" "hidden"
+	set_keysigning  "KEY1" "no"
+	set_zonesigning "KEY1" "no"
+	set_key_default_values "KEY2"
+	echo_i "check zone ${ZONE} after reconfig"
+	check_nsec3
+
+	# Zone: rsasha1-to-nsec3-wait.kasp.
+	set_zone_policy "rsasha1-to-nsec3-wait.kasp" "nsec3" 2 3600
+	set_server "ns3" "10.53.0.3"
+	set_key_rsasha1_values "KEY1"
+	set_key_states "KEY1" "hidden" "omnipresent" "omnipresent" "omnipresent" "omnipresent"
+	set_key_default_values "KEY2"
+	echo_i "check zone ${ZONE} after reconfig"
+
+	ret=0
+	wait_for_log 10 "zone $ZONE/IN (signed): wait building NSEC3 chain until NSEC only DNSKEYs are removed" ns3/named.run || ret=1
+	test "$ret" -eq 0 || echo_i "failed"
+	status=$((status+ret))
+
+	check_nsec
+
+	# Zone: nsec3-to-rsasha1.kasp.
+	set_zone_policy "nsec3-to-rsasha1.kasp" "rsasha1" 2 3600
+	set_nsec3param "1" "0" "0"
+	set_server "ns3" "10.53.0.3"
+	set_key_default_values "KEY1"
+	set_key_states  "KEY1" "hidden" "unretentive" "unretentive" "unretentive" "hidden"
+	set_keysigning  "KEY1" "no"
+	set_zonesigning "KEY1" "no"
+	set_key_rsasha1_values "KEY2"
+	echo_i "check zone ${ZONE} after reconfig"
+	check_nsec
+
+	# Zone: nsec3-to-rsasha1-ds.kasp.
+	set_zone_policy "nsec3-to-rsasha1-ds.kasp" "rsasha1" 2 3600
+	set_nsec3param "1" "0" "0"
+	set_server "ns3" "10.53.0.3"
+	set_key_default_values "KEY1"
+	set_key_states "KEY1" "hidden" "omnipresent" "omnipresent" "omnipresent" "omnipresent"
+	set_key_rsasha1_values "KEY2"
+	echo_i "check zone ${ZONE} after reconfig"
+	check_nsec
+
+	key_clear "KEY1"
+	key_clear "KEY2"
+fi
 
 # Zone: nsec3.kasp. (same)
-set_zone_policy "nsec3.kasp" "nsec3"
+set_zone_policy "nsec3.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} after reconfig"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-dyamic.kasp. (same)
-set_zone_policy "nsec3-dynamic.kasp" "nsec3"
+set_zone_policy "nsec3-dynamic.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} after reconfig"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-change.kasp. (reconfigured)
-set_zone_policy "nsec3-change.kasp" "nsec3-other"
+set_zone_policy "nsec3-change.kasp" "nsec3-other" 1 3600
 set_nsec3param "1" "11" "8"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} after reconfig"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-dynamic-change.kasp. (reconfigured)
-set_zone_policy "nsec3-dynamic-change.kasp" "nsec3-other"
+set_zone_policy "nsec3-dynamic-change.kasp" "nsec3-other" 1 3600
 set_nsec3param "1" "11" "8"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} after reconfig"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-to-nsec.kasp. (reconfigured)
-set_zone_policy "nsec3-to-nsec.kasp" "nsec"
+set_zone_policy "nsec3-to-nsec.kasp" "nsec" 1 3600
 set_nsec3param "1" "11" "8"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} after reconfig"
 check_nsec
-dnssec_verify
 
 # Zone: nsec3-to-optout.kasp. (reconfigured)
 # DISABLED:
 # There is a bug in the nsec3param building code that thinks when the
 # optout bit is changed, the chain already exists. [GL #2216]
-#set_zone_policy "nsec3-to-optout.kasp" "optout"
+#set_zone_policy "nsec3-to-optout.kasp" "optout" 1 3600
 #set_nsec3param "1" "0" "0"
+#set_key_default_values "KEY1"
 #echo_i "check zone ${ZONE} after reconfig"
 #check_nsec3
-#dnssec_verify
 
 # Zone: nsec3-from-optout.kasp. (reconfigured)
 # DISABLED:
 # There is a bug in the nsec3param building code that thinks when the
 # optout bit is changed, the chain already exists. [GL #2216]
-#set_zone_policy "nsec3-from-optout.kasp" "nsec3"
+#set_zone_policy "nsec3-from-optout.kasp" "nsec3" 1 3600
 #set_nsec3param "0" "0" "0"
+#set_key_default_values "KEY1"
 #echo_i "check zone ${ZONE} after reconfig"
 #check_nsec3
-#dnssec_verify
 
 # Zone: nsec3-other.kasp. (same)
-set_zone_policy "nsec3-other.kasp" "nsec3-other"
+set_zone_policy "nsec3-other.kasp" "nsec3-other" 1 3600
 set_nsec3param "1" "11" "8"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} after reconfig"
 check_nsec3
-dnssec_verify
 
 # Using rndc signing -nsec3param (should fail)
-set_zone_policy "nsec3-change.kasp" "nsec3-other"
+set_zone_policy "nsec3-change.kasp" "nsec3-other" 1 3600
 echo_i "use rndc signing -nsec3param ${ZONE} to change NSEC3 settings"
 rndccmd $SERVER signing -nsec3param 1 1 12 ffff $ZONE > rndc.signing.test$n.$ZONE || log_error "failed to call rndc signing -nsec3param $ZONE"
 grep "zone uses dnssec-policy, use rndc dnssec command instead" rndc.signing.test$n.$ZONE > /dev/null || log_error "rndc signing -nsec3param should fail"
 check_nsec3
-dnssec_verify
 
 # Test NSEC3 and NSEC3PARAM is the same after restart
-set_zone_policy "nsec3.kasp" "nsec3"
+set_zone_policy "nsec3.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} before restart"
 check_nsec3
-dnssec_verify
 
 # Restart named, NSEC3 should stay the same.
 ret=0
@@ -318,22 +481,22 @@ test "$ret" -eq 0 || echo_i "failed"
 status=$((status+ret))
 
 prevsalt="${SALT}"
-set_zone_policy "nsec3.kasp" "nsec3"
+set_zone_policy "nsec3.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 SALT="${prevsalt}"
 echo_i "check zone ${ZONE} after restart has salt ${SALT}"
 check_nsec3
-dnssec_verify
 
 # Zone: nsec3-fails-to-load.kasp. (should be fixed after reload)
 cp ns3/template.db.in ns3/nsec3-fails-to-load.kasp.db
 rndc_reload ns3 10.53.0.3
 
-set_zone_policy "nsec3-fails-to-load.kasp" "nsec3"
+set_zone_policy "nsec3-fails-to-load.kasp" "nsec3" 1 3600
 set_nsec3param "0" "0" "0"
+set_key_default_values "KEY1"
 echo_i "check zone ${ZONE} after reload"
 check_nsec3
-dnssec_verify
 
 echo_i "exit status: $status"
 [ $status -eq 0 ] || exit 1
diff --git a/doc/notes/notes-current.rst b/doc/notes/notes-current.rst
index ca4a6b79b6..ad45e432bc 100644
--- a/doc/notes/notes-current.rst
+++ b/doc/notes/notes-current.rst
@@ -38,6 +38,12 @@ Feature Changes
 - Zones using ``dnssec-policy`` now require dynamic DNS or
   ``inline-signing`` to be configured explicitly :gl:`#3381`.
 
+- When reconfiguring ``dnssec-policy`` from using NSEC with an NSEC-only DNSKEY
+  algorithm (e.g. RSASHA1) to a policy that uses NSEC3, BIND will no longer fail
+  to sign the zone, but keep using NSEC for a little longer until the offending
+  DNSKEY records have been removed from the zone, then switch to using NSEC3.
+  :gl:`#3486`
+
 Bug Fixes
 ~~~~~~~~~
 
diff --git a/lib/dns/include/dns/nsec.h b/lib/dns/include/dns/nsec.h
index 04029e2ff6..e68ea35ebf 100644
--- a/lib/dns/include/dns/nsec.h
+++ b/lib/dns/include/dns/nsec.h
@@ -19,6 +19,7 @@
 
 #include <isc/lang.h>
 
+#include <dns/diff.h>
 #include <dns/name.h>
 #include <dns/types.h>
 
@@ -60,11 +61,15 @@ dns_nsec_typepresent(dns_rdata_t *nsec, dns_rdatatype_t type);
  */
 
 isc_result_t
-dns_nsec_nseconly(dns_db_t *db, dns_dbversion_t *version, bool *answer);
+dns_nsec_nseconly(dns_db_t *db, dns_dbversion_t *version, dns_diff_t *diff,
+		  bool *answer);
 /*
  * Report whether the DNSKEY RRset has a NSEC only algorithm.  Unknown
  * algorithms are assumed to support NSEC3.  If DNSKEY is not found,
  * *answer is set to false, and ISC_R_NOTFOUND is returned.
+ * If 'diff' is provided, check if the NSEC only DNSKEY will be deleted.
+ * If so, and there are no other NSEC only DNSKEYs that will stay in 'db',
+ * consider the DNSKEY RRset to have no NSEC only DNSKEYs.
  *
  * Requires:
  * 	'answer' to be non NULL.
diff --git a/lib/dns/include/dns/zone.h b/lib/dns/include/dns/zone.h
index c9a1487928..0f035cf5a8 100644
--- a/lib/dns/include/dns/zone.h
+++ b/lib/dns/include/dns/zone.h
@@ -29,6 +29,7 @@
 #include <isc/tls.h>
 
 #include <dns/catz.h>
+#include <dns/diff.h>
 #include <dns/master.h>
 #include <dns/masterdump.h>
 #include <dns/rdatastruct.h>
@@ -2761,3 +2762,20 @@ dns_zone_gettid(dns_zone_t *zone);
  *
  * \return thread id associated with the zone
  */
+
+bool
+dns_zone_check_dnskey_nsec3(dns_zone_t *zone, dns_db_t *db,
+			    dns_dbversion_t *ver, dns_diff_t *diff,
+			    dst_key_t **keys, unsigned int numkeys);
+/**<
+ * Return whether the zone would enter an inconsistent state where NSEC only
+ * DNSKEYs are present along NSEC3 chains.
+ *
+ * Requires:
+ * \li	'zone' to be a valid zone.
+ * \li	'db'is not NULL.
+ *
+ * Returns:
+ * \li	'true' if the check passes, that is the zone remains consistent,
+ *	'false' if the zone would have NSEC only DNSKEYs and an NSEC3 chain.
+ */
diff --git a/lib/dns/nsec.c b/lib/dns/nsec.c
index afbe9c80f9..84c47d6c21 100644
--- a/lib/dns/nsec.c
+++ b/lib/dns/nsec.c
@@ -247,7 +247,8 @@ dns_nsec_typepresent(dns_rdata_t *nsec, dns_rdatatype_t type) {
 }
 
 isc_result_t
-dns_nsec_nseconly(dns_db_t *db, dns_dbversion_t *version, bool *answer) {
+dns_nsec_nseconly(dns_db_t *db, dns_dbversion_t *version, dns_diff_t *diff,
+		  bool *answer) {
 	dns_dbnode_t *node = NULL;
 	dns_rdataset_t rdataset;
 	dns_rdata_dnskey_t dnskey;
@@ -282,8 +283,35 @@ dns_nsec_nseconly(dns_db_t *db, dns_dbversion_t *version, bool *answer) {
 		RUNTIME_CHECK(result == ISC_R_SUCCESS);
 
 		if (dnskey.algorithm == DST_ALG_RSAMD5 ||
-		    dnskey.algorithm == DST_ALG_RSASHA1) {
-			break;
+		    dnskey.algorithm == DST_ALG_DH ||
+		    dnskey.algorithm == DST_ALG_DSA ||
+		    dnskey.algorithm == DST_ALG_RSASHA1)
+		{
+			bool deleted = false;
+			if (diff != NULL) {
+				for (dns_difftuple_t *tuple =
+					     ISC_LIST_HEAD(diff->tuples);
+				     tuple != NULL;
+				     tuple = ISC_LIST_NEXT(tuple, link))
+				{
+					if (tuple->rdata.type !=
+						    dns_rdatatype_dnskey ||
+					    tuple->op != DNS_DIFFOP_DEL) {
+						continue;
+					}
+
+					if (dns_rdata_compare(
+						    &rdata, &tuple->rdata) == 0)
+					{
+						deleted = true;
+						break;
+					}
+				}
+			}
+
+			if (!deleted) {
+				break;
+			}
 		}
 	}
 	dns_rdataset_disassociate(&rdataset);
diff --git a/lib/dns/zone.c b/lib/dns/zone.c
index d932b1b841..600fad94e5 100644
--- a/lib/dns/zone.c
+++ b/lib/dns/zone.c
@@ -3726,7 +3726,7 @@ zone_addnsec3chain(dns_zone_t *zone, dns_rdata_nsec3param_t *nsec3param) {
 	 * latter to exist in the first place.
 	 */
 	dns_db_currentversion(db, &version);
-	result = dns_nsec_nseconly(db, version, &nseconly);
+	result = dns_nsec_nseconly(db, version, NULL, &nseconly);
 	nsec3ok = (result == ISC_R_SUCCESS && !nseconly);
 	dns_db_closeversion(db, &version, false);
 	if (!nsec3ok && (nsec3param->flags & DNS_NSEC3FLAG_REMOVE) == 0) {
@@ -3918,7 +3918,7 @@ resume_addnsec3chain(dns_zone_t *zone) {
 	 * In order to create NSEC3 chains we need the DNSKEY RRset at zone
 	 * apex to exist and contain no keys using NSEC-only algorithms.
 	 */
-	result = dns_nsec_nseconly(db, version, &nseconly);
+	result = dns_nsec_nseconly(db, version, NULL, &nseconly);
 	nsec3ok = (result == ISC_R_SUCCESS && !nseconly);
 
 	/*
@@ -8186,7 +8186,7 @@ try_private:
 		goto add;
 	}
 
-	result = dns_nsec_nseconly(db, ver, &nseconly);
+	result = dns_nsec_nseconly(db, ver, diff, &nseconly);
 	nsec3ok = (result == ISC_R_SUCCESS && !nseconly);
 
 	/*
@@ -9508,6 +9508,105 @@ failure:
 	return (result);
 }
 
+/*
+ * Prevent the zone entering a inconsistent state where
+ * NSEC only DNSKEYs are present with NSEC3 chains.
+ */
+bool
+dns_zone_check_dnskey_nsec3(dns_zone_t *zone, dns_db_t *db,
+			    dns_dbversion_t *ver, dns_diff_t *diff,
+			    dst_key_t **keys, unsigned int numkeys) {
+	uint8_t alg;
+	dns_rdatatype_t privatetype;
+	;
+	bool nseconly = false, nsec3 = false;
+	isc_result_t result;
+
+	REQUIRE(DNS_ZONE_VALID(zone));
+	REQUIRE(db != NULL);
+
+	privatetype = dns_zone_getprivatetype(zone);
+
+	/* Scan the tuples for an NSEC-only DNSKEY */
+	if (diff != NULL) {
+		for (dns_difftuple_t *tuple = ISC_LIST_HEAD(diff->tuples);
+		     tuple != NULL; tuple = ISC_LIST_NEXT(tuple, link))
+		{
+			if (nseconly && nsec3) {
+				break;
+			}
+
+			if (tuple->op != DNS_DIFFOP_ADD) {
+				continue;
+			}
+
+			if (tuple->rdata.type == dns_rdatatype_nsec3param) {
+				nsec3 = true;
+			}
+
+			if (tuple->rdata.type != dns_rdatatype_dnskey) {
+				continue;
+			}
+
+			alg = tuple->rdata.data[3];
+			if (alg == DNS_KEYALG_RSAMD5 || alg == DNS_KEYALG_DH ||
+			    alg == DNS_KEYALG_DSA || alg == DNS_KEYALG_RSASHA1)
+			{
+				nseconly = true;
+			}
+		}
+	}
+	/* Scan the zone keys for an NSEC-only DNSKEY */
+	if (keys != NULL && !nseconly) {
+		for (unsigned int i = 0; i < numkeys; i++) {
+			alg = dst_key_alg(keys[i]);
+			if (alg == DNS_KEYALG_RSAMD5 || alg == DNS_KEYALG_DH ||
+			    alg == DNS_KEYALG_DSA || alg == DNS_KEYALG_RSASHA1)
+			{
+				nseconly = true;
+				break;
+			}
+		}
+	}
+
+	/* Check DB for NSEC-only DNSKEY */
+	if (!nseconly) {
+		result = dns_nsec_nseconly(db, ver, diff, &nseconly);
+		/*
+		 * Adding an NSEC3PARAM record can proceed without a
+		 * DNSKEY (it will trigger a delayed change), so we can
+		 * ignore ISC_R_NOTFOUND here.
+		 */
+		if (result == ISC_R_NOTFOUND) {
+			result = ISC_R_SUCCESS;
+		}
+		CHECK(result);
+	}
+
+	/* Check existing DB for NSEC3 */
+	if (!nsec3) {
+		CHECK(dns_nsec3_activex(db, ver, false, privatetype, &nsec3));
+	}
+
+	/* Check kasp for NSEC3PARAM settings */
+	if (!nsec3) {
+		dns_kasp_t *kasp = dns_zone_getkasp(zone);
+		if (kasp != NULL) {
+			nsec3 = dns_kasp_nsec3(kasp);
+		}
+	}
+
+	/* Refuse to allow NSEC3 with NSEC-only keys */
+	if (nseconly && nsec3) {
+		goto failure;
+	}
+
+	return (true);
+
+failure:
+	return (false);
+}
+
 /*
  * Incrementally sign the zone using the keys requested.
  * Builds the NSEC chain if required.
@@ -9643,6 +9742,15 @@ zone_sign(dns_zone_t *zone) {
 	/* Determine which type of chain to build */
 	if (use_kasp) {
 		build_nsec3 = dns_kasp_nsec3(kasp);
+		if (!dns_zone_check_dnskey_nsec3(zone, db, version, NULL,
+						 (dst_key_t **)&zone_keys,
+						 nkeys))
+		{
+			dnssec_log(zone, ISC_LOG_INFO,
+				   "wait building NSEC3 chain until NSEC only "
+				   "DNSKEYs are removed");
+			build_nsec3 = false;
+		}
 		build_nsec = !build_nsec3;
 	} else {
 		CHECK(dns_private_chains(db, version, zone->privatetype,
@@ -20506,63 +20614,6 @@ failure:
 	return (result);
 }
 
-/*
- * Prevent the zone entering a inconsistent state where
- * NSEC only DNSKEYs are present with NSEC3 chains.
- * See update.c:check_dnssec()
- */
-static bool
-dnskey_sane(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
-	    dns_diff_t *diff) {
-	isc_result_t result;
-	dns_difftuple_t *tuple;
-	bool nseconly = false, nsec3 = false;
-	dns_rdatatype_t privatetype = dns_zone_getprivatetype(zone);
-
-	/* Scan the tuples for an NSEC-only DNSKEY */
-	for (tuple = ISC_LIST_HEAD(diff->tuples); tuple != NULL;
-	     tuple = ISC_LIST_NEXT(tuple, link))
-	{
-		uint8_t alg;
-		if (tuple->rdata.type != dns_rdatatype_dnskey ||
-		    tuple->op != DNS_DIFFOP_ADD) {
-			continue;
-		}
-
-		alg = tuple->rdata.data[3];
-		if (alg == DST_ALG_RSASHA1) {
-			nseconly = true;
-			break;
-		}
-	}
-
-	/* Check existing DB for NSEC-only DNSKEY */
-	if (!nseconly) {
-		result = dns_nsec_nseconly(db, ver, &nseconly);
-		if (result == ISC_R_NOTFOUND) {
-			result = ISC_R_SUCCESS;
-		}
-		CHECK(result);
-	}
-
-	/* Check existing DB for NSEC3 */
-	if (!nsec3) {
-		CHECK(dns_nsec3_activex(db, ver, false, privatetype, &nsec3));
-	}
-
-	/* Refuse to allow NSEC3 with NSEC-only keys */
-	if (nseconly && nsec3) {
-		dnssec_log(zone, ISC_LOG_ERROR,
-			   "NSEC only DNSKEYs and NSEC3 chains not allowed");
-		goto failure;
-	}
-
-	return (true);
-
-failure:
-	return (false);
-}
-
 static isc_result_t
 clean_nsec3param(dns_zone_t *zone, dns_db_t *db, dns_dbversion_t *ver,
 		 dns_diff_t *diff) {
@@ -21558,6 +21609,7 @@ zone_rekey(dns_zone_t *zone) {
 	if (result == ISC_R_SUCCESS) {
 		bool cdsdel = false;
 		bool cdnskeydel = false;
+		bool sane_diff, sane_dnskey;
 		isc_stdtime_t when;
 
 		/*
@@ -21726,9 +21778,21 @@ zone_rekey(dns_zone_t *zone) {
 			}
 		}
 
-		if ((newactive || fullsign || !ISC_LIST_EMPTY(diff.tuples)) &&
-		    dnskey_sane(zone, db, ver, &diff))
-		{
+		/*
+		 * A sane diff is one that is not empty, and that does not
+		 * introduce a zone with NSEC only DNSKEYs along with NSEC3
+		 * chains.
+		 */
+		sane_dnskey = dns_zone_check_dnskey_nsec3(zone, db, ver, &diff,
+							  NULL, 0);
+		sane_diff = !ISC_LIST_EMPTY(diff.tuples) && sane_dnskey;
+		if (!sane_dnskey) {
+			dnssec_log(zone, ISC_LOG_ERROR,
+				   "NSEC only DNSKEYs and NSEC3 chains not "
+				   "allowed");
+		}
+
+		if (newactive || fullsign || sane_diff) {
 			CHECK(dns_diff_apply(&diff, db, ver));
 			CHECK(clean_nsec3param(zone, db, ver, &diff));
 			CHECK(add_signing_records(db, zone->privatetype, ver,
@@ -22913,7 +22977,7 @@ rss_post(dns_zone_t *zone, isc_event_t *event) {
 		dns_rdata_init(&rdata);
 
 		np->data[2] |= DNS_NSEC3FLAG_CREATE;
-		result = dns_nsec_nseconly(db, newver, &nseconly);
+		result = dns_nsec_nseconly(db, newver, NULL, &nseconly);
 		if (result == ISC_R_NOTFOUND || nseconly) {
 			np->data[2] |= DNS_NSEC3FLAG_INITIAL;
 		}
diff --git a/lib/ns/update.c b/lib/ns/update.c
index 28b59a5484..4b32b7508f 100644
--- a/lib/ns/update.c
+++ b/lib/ns/update.c
@@ -2096,56 +2096,12 @@ failure:
 static isc_result_t
 check_dnssec(ns_client_t *client, dns_zone_t *zone, dns_db_t *db,
 	     dns_dbversion_t *ver, dns_diff_t *diff) {
-	dns_difftuple_t *tuple;
-	bool nseconly = false, nsec3 = false;
 	isc_result_t result;
 	unsigned int iterations = 0;
 	dns_rdatatype_t privatetype = dns_zone_getprivatetype(zone);
 
-	/* Scan the tuples for an NSEC-only DNSKEY or an NSEC3PARAM */
-	for (tuple = ISC_LIST_HEAD(diff->tuples); tuple != NULL;
-	     tuple = ISC_LIST_NEXT(tuple, link))
-	{
-		if (tuple->op != DNS_DIFFOP_ADD) {
-			continue;
-		}
-
-		if (tuple->rdata.type == dns_rdatatype_dnskey) {
-			uint8_t alg;
-			alg = tuple->rdata.data[3];
-			if (alg == DST_ALG_RSASHA1) {
-				nseconly = true;
-				break;
-			}
-		} else if (tuple->rdata.type == dns_rdatatype_nsec3param) {
-			nsec3 = true;
-			break;
-		}
-	}
-
-	/* Check existing DB for NSEC-only DNSKEY */
-	if (!nseconly) {
-		result = dns_nsec_nseconly(db, ver, &nseconly);
-
-		/*
-		 * An NSEC3PARAM update can proceed without a DNSKEY (it
-		 * will trigger a delayed change), so we can ignore
-		 * ISC_R_NOTFOUND here.
-		 */
-		if (result == ISC_R_NOTFOUND) {
-			result = ISC_R_SUCCESS;
-		}
-
-		CHECK(result);
-	}
-
-	/* Check existing DB for NSEC3 */
-	if (!nsec3) {
-		CHECK(dns_nsec3_activex(db, ver, false, privatetype, &nsec3));
-	}
-
 	/* Refuse to allow NSEC3 with NSEC-only keys */
-	if (nseconly && nsec3) {
+	if (!dns_zone_check_dnskey_nsec3(zone, db, ver, diff, NULL, 0)) {
 		update_log(client, zone, ISC_LOG_ERROR,
 			   "NSEC only DNSKEYs and NSEC3 chains not allowed");
 		result = DNS_R_REFUSED;
@@ -2346,8 +2302,11 @@ add_nsec3param_records(ns_client_t *client, dns_zone_t *zone, dns_db_t *db,
 			 * supporting an NSEC3 chain, then we set the
 			 * INITIAL flag to indicate that these parameters
 			 * are to be used later.
+			 *
+			 * Don't provide a 'diff' here because we want to
+			 * know the capability of the current database.
 			 */
-			result = dns_nsec_nseconly(db, ver, &nseconly);
+			result = dns_nsec_nseconly(db, ver, NULL, &nseconly);
 			if (result == ISC_R_NOTFOUND || nseconly) {
 				buf[2] |= DNS_NSEC3FLAG_INITIAL;
 			}