diff --git a/src/Umbraco.Web.UI.Client/src/packages/documents/document-types/components/input-document-type/input-document-type.element.ts b/src/Umbraco.Web.UI.Client/src/packages/documents/document-types/components/input-document-type/input-document-type.element.ts
index d5188883b5..f94569be96 100644
--- a/src/Umbraco.Web.UI.Client/src/packages/documents/document-types/components/input-document-type/input-document-type.element.ts
+++ b/src/Umbraco.Web.UI.Client/src/packages/documents/document-types/components/input-document-type/input-document-type.element.ts
@@ -8,10 +8,13 @@ import { UmbChangeEvent } from '@umbraco-cms/backoffice/event';
 import { UmbLitElement } from '@umbraco-cms/backoffice/lit-element';
 import { UmbModalRouteRegistrationController } from '@umbraco-cms/backoffice/router';
 import { UmbSorterController } from '@umbraco-cms/backoffice/sorter';
-import { UUIFormControlMixin } from '@umbraco-cms/backoffice/external/uui';
+import { UmbFormControlMixin } from '@umbraco-cms/backoffice/validation';
 
 @customElement('umb-input-document-type')
-export class UmbInputDocumentTypeElement extends UUIFormControlMixin(UmbLitElement, '') {
+export class UmbInputDocumentTypeElement extends UmbFormControlMixin<string | undefined, typeof UmbLitElement>(
+	UmbLitElement,
+	undefined,
+) {
 	#sorter = new UmbSorterController<string>(this, {
 		getUniqueOfElement: (element) => {
 			return element.id;
@@ -102,11 +105,11 @@ export class UmbInputDocumentTypeElement extends UUIFormControlMixin(UmbLitEleme
 	}
 
 	@property()
-	public set value(uniques: string) {
+	public set value(uniques: string | undefined) {
 		this.selection = splitStringToArray(uniques);
 	}
-	public get value(): string {
-		return this.selection.join(',');
+	public get value(): string | undefined {
+		return this.selection.length > 0 ? this.selection.join(',') : undefined;
 	}
 	@state()
 	private _items?: Array<UmbDocumentTypeItemModel>;
diff --git a/src/Umbraco.Web.UI.Client/src/packages/documents/document-types/property-editors/document-type-picker/property-editor-ui-document-type-picker.element.ts b/src/Umbraco.Web.UI.Client/src/packages/documents/document-types/property-editors/document-type-picker/property-editor-ui-document-type-picker.element.ts
index 5cfb04658f..a14f100082 100644
--- a/src/Umbraco.Web.UI.Client/src/packages/documents/document-types/property-editors/document-type-picker/property-editor-ui-document-type-picker.element.ts
+++ b/src/Umbraco.Web.UI.Client/src/packages/documents/document-types/property-editors/document-type-picker/property-editor-ui-document-type-picker.element.ts
@@ -35,7 +35,7 @@ export class UmbPropertyEditorUIDocumentTypePickerElement extends UmbLitElement
 	onlyElementTypes?: boolean;
 
 	#onChange(event: CustomEvent & { target: UmbInputDocumentTypeElement }) {
-		this.value = event.target.selection.join(',');
+		this.value = event.target.value;
 		this.dispatchEvent(new UmbPropertyValueChangeEvent());
 	}