diff --git a/cmd/k8s-operator/ingress.go b/cmd/k8s-operator/ingress.go
index 1e042c1f7..72291afe8 100644
--- a/cmd/k8s-operator/ingress.go
+++ b/cmd/k8s-operator/ingress.go
@@ -125,6 +125,10 @@ func (a *IngressReconciler) maybeProvision(ctx context.Context, logger *zap.Suga
 	gaugeIngressResources.Set(int64(a.managedIngresses.Len()))
 	a.mu.Unlock()
 
+	if !a.ssr.IsHTTPSEnabledOnTailnet() {
+		a.recorder.Event(ing, corev1.EventTypeWarning, "HTTPSNotEnabled", "HTTPS is not enabled on the tailnet; ingress may not work")
+	}
+
 	// magic443 is a fake hostname that we can use to tell containerboot to swap
 	// out with the real hostname once it's known.
 	const magic443 = "${TS_CERT_DOMAIN}:443"
diff --git a/cmd/k8s-operator/operator.go b/cmd/k8s-operator/operator.go
index 139101cc8..5d78f4c25 100644
--- a/cmd/k8s-operator/operator.go
+++ b/cmd/k8s-operator/operator.go
@@ -73,7 +73,7 @@ func main() {
 	if shouldRunAuthProxy {
 		launchAuthProxy(zlog, restConfig, s)
 	}
-	startReconcilers(zlog, tsNamespace, restConfig, tsClient, image, priorityClassName, tags)
+	startReconcilers(zlog, s, tsNamespace, restConfig, tsClient, image, priorityClassName, tags)
 }
 
 // initTSNet initializes the tsnet.Server and logs in to Tailscale. It uses the
@@ -182,7 +182,7 @@ waitOnline:
 
 // startReconcilers starts the controller-runtime manager and registers the
 // ServiceReconciler.
-func startReconcilers(zlog *zap.SugaredLogger, tsNamespace string, restConfig *rest.Config, tsClient *tailscale.Client, image, priorityClassName, tags string) {
+func startReconcilers(zlog *zap.SugaredLogger, s *tsnet.Server, tsNamespace string, restConfig *rest.Config, tsClient *tailscale.Client, image, priorityClassName, tags string) {
 	var (
 		isDefaultLoadBalancer = defaultBool("OPERATOR_DEFAULT_LOAD_BALANCER", false)
 	)
@@ -225,6 +225,7 @@ func startReconcilers(zlog *zap.SugaredLogger, tsNamespace string, restConfig *r
 	eventRecorder := mgr.GetEventRecorderFor("tailscale-operator")
 	ssr := &tailscaleSTSReconciler{
 		Client:                 mgr.GetClient(),
+		tsnetServer:            s,
 		tsClient:               tsClient,
 		defaultTags:            strings.Split(tags, ","),
 		operatorNamespace:      tsNamespace,
diff --git a/cmd/k8s-operator/sts.go b/cmd/k8s-operator/sts.go
index a706835a2..31aa6bad7 100644
--- a/cmd/k8s-operator/sts.go
+++ b/cmd/k8s-operator/sts.go
@@ -24,6 +24,7 @@ import (
 	"tailscale.com/client/tailscale"
 	"tailscale.com/ipn"
 	"tailscale.com/tailcfg"
+	"tailscale.com/tsnet"
 	"tailscale.com/types/opt"
 	"tailscale.com/util/dnsname"
 	"tailscale.com/util/mak"
@@ -71,6 +72,7 @@ type tailscaleSTSConfig struct {
 
 type tailscaleSTSReconciler struct {
 	client.Client
+	tsnetServer            *tsnet.Server
 	tsClient               tsClient
 	defaultTags            []string
 	operatorNamespace      string
@@ -78,6 +80,11 @@ type tailscaleSTSReconciler struct {
 	proxyPriorityClassName string
 }
 
+// IsHTTPSEnabledOnTailnet reports whether HTTPS is enabled on the tailnet.
+func (a *tailscaleSTSReconciler) IsHTTPSEnabledOnTailnet() bool {
+	return len(a.tsnetServer.CertDomains()) > 0
+}
+
 // Provision ensures that the StatefulSet for the given service is running and
 // up to date.
 func (a *tailscaleSTSReconciler) Provision(ctx context.Context, logger *zap.SugaredLogger, sts *tailscaleSTSConfig) (*corev1.Service, error) {