diff --git a/bundle.yaml b/bundle.yaml
index e8f5ea83ebf..2dbe70ef440 100644
--- a/bundle.yaml
+++ b/bundle.yaml
@@ -3080,7 +3080,6 @@ spec:
                           parseMode:
                             description: Parse mode for telegram message
                             enum:
-                            - ""
                             - MarkdownV2
                             - Markdown
                             - HTML
diff --git a/example/prometheus-operator-crd/monitoring.coreos.com_alertmanagerconfigs.yaml b/example/prometheus-operator-crd/monitoring.coreos.com_alertmanagerconfigs.yaml
index cc9728443ce..063b604dd57 100644
--- a/example/prometheus-operator-crd/monitoring.coreos.com_alertmanagerconfigs.yaml
+++ b/example/prometheus-operator-crd/monitoring.coreos.com_alertmanagerconfigs.yaml
@@ -3080,7 +3080,6 @@ spec:
                           parseMode:
                             description: Parse mode for telegram message
                             enum:
-                            - ""
                             - MarkdownV2
                             - Markdown
                             - HTML
diff --git a/jsonnet/prometheus-operator/alertmanagerconfigs-crd.json b/jsonnet/prometheus-operator/alertmanagerconfigs-crd.json
index a06027e8e52..f7c70adb5fb 100644
--- a/jsonnet/prometheus-operator/alertmanagerconfigs-crd.json
+++ b/jsonnet/prometheus-operator/alertmanagerconfigs-crd.json
@@ -3241,7 +3241,6 @@
                               "parseMode": {
                                 "description": "Parse mode for telegram message",
                                 "enum": [
-                                  "",
                                   "MarkdownV2",
                                   "Markdown",
                                   "HTML"
diff --git a/pkg/apis/monitoring/v1alpha1/alertmanager_config_types.go b/pkg/apis/monitoring/v1alpha1/alertmanager_config_types.go
index 86a1f4d33d1..7643bc47aea 100644
--- a/pkg/apis/monitoring/v1alpha1/alertmanager_config_types.go
+++ b/pkg/apis/monitoring/v1alpha1/alertmanager_config_types.go
@@ -789,10 +789,8 @@ type TelegramConfig struct {
 	// Telegram bot token
 	// The secret needs to be in the same namespace as the AlertmanagerConfig
 	// object and accessible by the Prometheus Operator.
-	// +kubebuilder:validation:Required
 	BotToken *v1.SecretKeySelector `json:"botToken,omitempty"`
 	// The Telegram chat ID.
-	// +kubebuilder:validation:Required
 	ChatID int64 `json:"chatID,omitempty"`
 	// Message template
 	// +optional
@@ -801,7 +799,7 @@ type TelegramConfig struct {
 	// +optional
 	DisableNotifications *bool `json:"disableNotifications,omitempty"`
 	// Parse mode for telegram message
-	//+kubebuilder:validation:Enum="";MarkdownV2;Markdown;HTML
+	//+kubebuilder:validation:Enum=MarkdownV2;Markdown;HTML
 	// +optional
 	ParseMode string `json:"parseMode,omitempty"`
 	// HTTP client configuration.