diff --git a/operators/pkg/controller/elasticsearch/driver/default.go b/operators/pkg/controller/elasticsearch/driver/default.go
index a00790a2e7..f145753872 100644
--- a/operators/pkg/controller/elasticsearch/driver/default.go
+++ b/operators/pkg/controller/elasticsearch/driver/default.go
@@ -173,6 +173,8 @@ func (d *defaultDriver) Reconcile(
 		min = &d.Version
 	}
 
+	warnUnsupportedDistro(resourcesState.AllPods, reconcileState.Recorder)
+
 	observedState := d.observedStateResolver(
 		k8s.ExtractNamespacedName(&es),
 		certificateResources.TrustedHTTPCertificates,
@@ -545,3 +547,18 @@ func reconcileScriptsConfigMap(c k8s.Client, scheme *runtime.Scheme, es v1alpha1
 
 	return nil
 }
+
+// warnUnsupportedDistro sends an event of type warning if the Elasticsearch Docker image is not a supported
+// distribution by looking at if the prepare fs init container terminated with the UnsupportedDistro exit code.
+func warnUnsupportedDistro(pods []corev1.Pod, recorder *events.Recorder) {
+	for _, p := range pods {
+		for _, s := range p.Status.InitContainerStatuses {
+			state := s.LastTerminationState.Terminated
+			if s.Name == initcontainer.PrepareFilesystemContainerName &&
+				state != nil && state.ExitCode == initcontainer.UnsupportedDistroExitCode {
+				recorder.AddEvent(corev1.EventTypeWarning, events.EventReasonUnexpected,
+					"Unsupported distribution")
+			}
+		}
+	}
+}
diff --git a/operators/pkg/controller/elasticsearch/initcontainer/initcontainer.go b/operators/pkg/controller/elasticsearch/initcontainer/initcontainer.go
index 639100a7f5..3dcb682d48 100644
--- a/operators/pkg/controller/elasticsearch/initcontainer/initcontainer.go
+++ b/operators/pkg/controller/elasticsearch/initcontainer/initcontainer.go
@@ -18,7 +18,7 @@ const (
 	// osSettingsContainerName is the name of the container that tweaks os-level settings
 	osSettingsContainerName = "elastic-internal-init-os-settings"
 	// prepareFilesystemContainerName is the name of the container that prepares the filesystem
-	prepareFilesystemContainerName = "elastic-internal-init-filesystem"
+	PrepareFilesystemContainerName = "elastic-internal-init-filesystem"
 )
 
 // NewInitContainers creates init containers according to the given parameters
diff --git a/operators/pkg/controller/elasticsearch/initcontainer/prepare_fs.go b/operators/pkg/controller/elasticsearch/initcontainer/prepare_fs.go
index ad714ec899..69cc6a6886 100644
--- a/operators/pkg/controller/elasticsearch/initcontainer/prepare_fs.go
+++ b/operators/pkg/controller/elasticsearch/initcontainer/prepare_fs.go
@@ -105,7 +105,7 @@ func NewPrepareFSInitContainer(
 	container := corev1.Container{
 		Image:           imageName,
 		ImagePullPolicy: corev1.PullIfNotPresent,
-		Name:            prepareFilesystemContainerName,
+		Name:            PrepareFilesystemContainerName,
 		SecurityContext: &corev1.SecurityContext{
 			Privileged: &privileged,
 		},
diff --git a/operators/pkg/controller/elasticsearch/initcontainer/prepare_fs_script.go b/operators/pkg/controller/elasticsearch/initcontainer/prepare_fs_script.go
index f7b56765f5..aa2af79ec6 100644
--- a/operators/pkg/controller/elasticsearch/initcontainer/prepare_fs_script.go
+++ b/operators/pkg/controller/elasticsearch/initcontainer/prepare_fs_script.go
@@ -6,6 +6,7 @@ package initcontainer
 
 import (
 	"bytes"
+	"fmt"
 	"html/template"
 )
 
@@ -30,7 +31,10 @@ func RenderScriptTemplate(params TemplateParams) (string, error) {
 	return tplBuffer.String(), nil
 }
 
-const PrepareFsScriptConfigKey = "prepare-fs.sh"
+const (
+	PrepareFsScriptConfigKey  = "prepare-fs.sh"
+	UnsupportedDistroExitCode = 42
+)
 
 // scriptTemplate is the main script to be run
 // in the prepare-fs init container before ES starts
@@ -39,6 +43,13 @@ var scriptTemplate = template.Must(template.New("").Parse(
 
 	set -eu
 
+	# the operator only works with the default ES distribution
+	license=/usr/share/elasticsearch/LICENSE.txt
+	if [[ ! -f $license || $(grep -Fxc "ELASTIC LICENSE AGREEMENT" $license) -ne 1 ]]; then
+		>&2 echo "unsupported_distribution"
+		exit ` + fmt.Sprintf("%d", UnsupportedDistroExitCode) + `
+	fi
+
 	# compute time in seconds since the given start time
 	function duration() {
 		local start=$1