diff --git a/src/Umbraco.Web.UI.Client/src/libs/extension-api/functions/load-manifest-api.function.ts b/src/Umbraco.Web.UI.Client/src/libs/extension-api/functions/load-manifest-api.function.ts
index fbe291a2c7..ed9db89316 100644
--- a/src/Umbraco.Web.UI.Client/src/libs/extension-api/functions/load-manifest-api.function.ts
+++ b/src/Umbraco.Web.UI.Client/src/libs/extension-api/functions/load-manifest-api.function.ts
@@ -4,7 +4,7 @@ import type { ApiLoaderExports, ApiLoaderProperty, ClassConstructor, ElementAndA
 export async function loadManifestApi<ApiType extends UmbApi>(property: ApiLoaderProperty<ApiType> | ElementAndApiLoaderProperty<any, ApiType>): Promise<ClassConstructor<ApiType> | undefined> {
 	const propType = typeof property
 	if(propType === 'function') {
-		if(typeof property.constructor === 'function') {
+		if((property as ClassConstructor).prototype) {
 			// Class Constructor
 			return property as ClassConstructor<ApiType>;
 		} else {
diff --git a/src/Umbraco.Web.UI.Client/src/libs/extension-api/functions/load-manifest-element.function.ts b/src/Umbraco.Web.UI.Client/src/libs/extension-api/functions/load-manifest-element.function.ts
index a176af6c11..b1fcd616d8 100644
--- a/src/Umbraco.Web.UI.Client/src/libs/extension-api/functions/load-manifest-element.function.ts
+++ b/src/Umbraco.Web.UI.Client/src/libs/extension-api/functions/load-manifest-element.function.ts
@@ -4,7 +4,7 @@ import type { ApiLoaderExports, ClassConstructor, ElementAndApiLoaderProperty, E
 export async function loadManifestElement<ElementType extends HTMLElement>(property: ElementLoaderProperty<ElementType> | ElementAndApiLoaderProperty<ElementType>): Promise<ClassConstructor<ElementType> | undefined> {
 	const propType = typeof property
 	if(propType === 'function') {
-		if(typeof property.constructor === 'function') {
+		if((property as ClassConstructor).prototype) {
 			// Class Constructor
 			return property as ClassConstructor<ElementType>;
 		} else {