diff --git a/pkg/admission/pluginpreset_webhook.go b/pkg/admission/pluginpreset_webhook.go
index 4020fe77f..7b4219944 100644
--- a/pkg/admission/pluginpreset_webhook.go
+++ b/pkg/admission/pluginpreset_webhook.go
@@ -19,6 +19,8 @@ import (
 
 // Webhook for the PluginPreset custom resource.
 
+const preventDeletionAnnotation = "greenhouse.sap/prevent-deletion"
+
 func SetupPluginPresetWebhookWithManager(mgr ctrl.Manager) error {
 	return setupWebhook(mgr,
 		&greenhousev1alpha1.PluginPreset{},
@@ -116,9 +118,9 @@ func ValidateDeletePluginPreset(_ context.Context, _ client.Client, obj runtime.
 	}
 
 	var allErrs field.ErrorList
-	if _, ok := pluginPreset.Annotations["greenhouse.sap/prevent-deletion"]; ok {
-		allErrs = append(allErrs, field.Invalid(field.NewPath("metadata").Child("annotation").Child("greenhouse.sap/prevent-deletion"), pluginPreset.Annotations,
-			"Plugin preset has prevent deletion annotation"))
+	if _, ok := pluginPreset.Annotations[preventDeletionAnnotation]; ok {
+		allErrs = append(allErrs, field.Invalid(field.NewPath("metadata").Child("annotation").Child(preventDeletionAnnotation),
+			pluginPreset.Annotations, "Plugin preset has prevent deletion annotation"))
 	}
 
 	if len(allErrs) > 0 {
diff --git a/pkg/admission/pluginpreset_webhook_test.go b/pkg/admission/pluginpreset_webhook_test.go
index 3a4401741..0bd53a02a 100644
--- a/pkg/admission/pluginpreset_webhook_test.go
+++ b/pkg/admission/pluginpreset_webhook_test.go
@@ -170,4 +170,35 @@ var _ = Describe("PluginPreset Admission Tests", Ordered, func() {
 		Expect(test.K8sClient.Delete(test.Ctx, cut)).
 			To(Succeed(), "there must be no error deleting the PluginPreset")
 	})
+
+	It("should reject delete operation when PluginPreset has prevent deletion annotation", func() {
+		pluginPreset := &greenhousev1alpha1.PluginPreset{
+			ObjectMeta: metav1.ObjectMeta{
+				Name:      pluginPresetUpdate,
+				Namespace: test.TestNamespace,
+				Annotations: map[string]string{
+					preventDeletionAnnotation: "true",
+				},
+			},
+			Spec: greenhousev1alpha1.PluginPresetSpec{
+				Plugin: greenhousev1alpha1.PluginSpec{
+					PluginDefinition: pluginPresetDefinition,
+				},
+				ClusterSelector: metav1.LabelSelector{MatchLabels: map[string]string{"foo": "bar"}},
+			},
+		}
+
+		err := test.K8sClient.Create(test.Ctx, pluginPreset)
+		Expect(err).ToNot(HaveOccurred())
+
+		err = test.K8sClient.Delete(test.Ctx, pluginPreset)
+		Expect(err).To(HaveOccurred())
+
+		pluginPreset.Annotations = map[string]string{}
+		err = test.K8sClient.Update(test.Ctx, pluginPreset)
+		Expect(err).ToNot(HaveOccurred())
+
+		err = test.K8sClient.Delete(test.Ctx, pluginPreset)
+		Expect(err).ToNot(HaveOccurred())
+	})
 })