diff --git a/kubernetes/files/kube-addons/coredns/coredns-cm.yml b/kubernetes/files/kube-addons/coredns/coredns-cm.yml
index c9ce8a5..e4e85c7 100644
--- a/kubernetes/files/kube-addons/coredns/coredns-cm.yml
+++ b/kubernetes/files/kube-addons/coredns/coredns-cm.yml
@@ -24,7 +24,7 @@
           pods insecure
           upstream
 {%- if common.addons.externaldns.enabled and common.addons.externaldns.domain == common.addons.coredns.domain %}
-          fallthrough {{ common.addons.coredns.domain }} in-addr.arpa ip6.arpa
+          fallthrough {{ common.addons.coredns.domain|replace('_', '-') }} in-addr.arpa ip6.arpa
 {%- else %}
           fallthrough in-addr.arpa ip6.arpa
 {%- endif %}
@@ -37,7 +37,7 @@
         }
 {%- endif %}
 {%- if common.addons.externaldns.enabled %}
-        etcd {{ common.addons.externaldns.domain }} {
+        etcd {{ common.addons.externaldns.domain|replace('_', '-') }} {
           stubzones
           path /skydns
           endpoint http://{{ common.addons.coredns.etcd.client_address }}:2379
diff --git a/kubernetes/files/kube-addons/externaldns/externaldns-deploy.yml b/kubernetes/files/kube-addons/externaldns/externaldns-deploy.yml
index b01b163..4eb1467 100644
--- a/kubernetes/files/kube-addons/externaldns/externaldns-deploy.yml
+++ b/kubernetes/files/kube-addons/externaldns/externaldns-deploy.yml
@@ -34,7 +34,7 @@
         args:
         - --source=service
         - --source=ingress
-        - --domain-filter={{ common.addons.externaldns.domain }} # will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
+        - --domain-filter={{ common.addons.externaldns.domain|replace('_', '-') }} # will make ExternalDNS see only the hosted zones matching provided domain, omit to process all available hosted zones
         - --provider={{ common.addons.externaldns.provider }}
         {%- if common.addons.externaldns.provider == "google" %}
         - --google-project={{ common.addons.externaldns.google_options.project }}