diff --git a/bin/tests/system/dialup/ns1/named.conf.in b/bin/tests/system/dialup/ns1/named.conf.in
index 4b8302bcfa..a9c6777509 100644
--- a/bin/tests/system/dialup/ns1/named.conf.in
+++ b/bin/tests/system/dialup/ns1/named.conf.in
@@ -21,7 +21,7 @@ options {
 	pid-file "named.pid";
 	listen-on { 10.53.0.1; };
 	listen-on-v6 { none; };
-	heartbeat-interval 2;
+	heartbeat-interval 1;
 	recursion no;
 	dnssec-validation no;
 };
diff --git a/bin/tests/system/dialup/ns2/named.conf.in b/bin/tests/system/dialup/ns2/named.conf.in
index 382f5ce9a4..166b463189 100644
--- a/bin/tests/system/dialup/ns2/named.conf.in
+++ b/bin/tests/system/dialup/ns2/named.conf.in
@@ -21,7 +21,7 @@ options {
 	pid-file "named.pid";
 	listen-on { 10.53.0.2; };
 	listen-on-v6 { none; };
-	heartbeat-interval 2;
+	heartbeat-interval 1;
 	recursion no;
 	dnssec-validation no;
 };
diff --git a/bin/tests/system/dialup/ns3/named.conf.in b/bin/tests/system/dialup/ns3/named.conf.in
index 054a65893c..31b9a128c3 100644
--- a/bin/tests/system/dialup/ns3/named.conf.in
+++ b/bin/tests/system/dialup/ns3/named.conf.in
@@ -21,7 +21,7 @@ options {
 	pid-file "named.pid";
 	listen-on { 10.53.0.3; };
 	listen-on-v6 { none; };
-	heartbeat-interval 2;
+	heartbeat-interval 1;
 	recursion no;
 	dnssec-validation no;
 };