diff --git a/mariadb/files/nginx.tmpl b/mariadb/files/nginx.tmpl
index 5ec3d0db6d..356fad5025 100644
--- a/mariadb/files/nginx.tmpl
+++ b/mariadb/files/nginx.tmpl
@@ -473,11 +473,11 @@ stream {
     {{ range $j, $endpoint := $tcpServer.Endpoints }}
     {{ if eq $j 0 }}
         # NOTE(portdirect): see https://docs.nginx.com/nginx/admin-guide/load-balancer/tcp-health-check/#passive-tcp-health-checks to tune passive healthchecks
-        server                  {{ $endpoint.Address }}:{{ $endpoint.Port }};
+        server                  {{ formatIP $endpoint.Address }}:{{ $endpoint.Port }};
     {{ else if eq $j 1 }}
-        server                  {{ $endpoint.Address }}:{{ $endpoint.Port }} backup;
+        server                  {{ formatIP $endpoint.Address }}:{{ $endpoint.Port }} backup;
     {{ else }}
-        server                  {{ $endpoint.Address }}:{{ $endpoint.Port }} down;
+        server                  {{ formatIP $endpoint.Address }}:{{ $endpoint.Port }} down;
     {{ end }}
     {{ end }}
     }