diff --git a/apps/overlays/au-syd1/externaldns/values.yaml b/apps/overlays/au-syd1/externaldns/values.yaml
index e1d4281..7205050 100644
--- a/apps/overlays/au-syd1/externaldns/values.yaml
+++ b/apps/overlays/au-syd1/externaldns/values.yaml
@@ -52,6 +52,12 @@ extraArgs:
   # the forward zone (the reverse zone + resolver forwarder exist since #288;
   # without this flag nothing writes PTRs).
   - --create-ptr
+  # --create-ptr requires PTR in the managed record types; setting the flag
+  # replaces the default list (A,AAAA,CNAME), so re-state the defaults too.
+  - --managed-record-types=A
+  - --managed-record-types=AAAA
+  - --managed-record-types=CNAME
+  - --managed-record-types=PTR
   - --rfc2136-tsig-keyname=externaldns-key
   - --rfc2136-tsig-secret-alg=$(EXTERNAL_DNS_RFC2136_TSIG_ALGORITHM)
   - --rfc2136-tsig-axfr