don't be too strict

src/decorators/register.ts

@@ -142,11 +142,9 @@ function applySchemaForClass<T>(
   return instance;
 }
 
-export function RegisterSchema(options: SchemaClassOptions = {}) {
-  return function <T>(originalClass: ClassType<T>) {
-    Metadata.set('SchemaClassOptions', options)(originalClass);
+export function SchemaClass<T>(originalClass: ClassType<T>) {
   const schema = schemaFromClass(originalClass);
-    const newClass = (function (...args: any[]): any {
+  const newClass = (function (...args: any[]): T {
     const instance = new originalClass(...args);
     const originalObject = args[0];
     return applySchemaForClass(originalClass, instance, originalObject);
@@ -161,6 +159,12 @@ export function RegisterSchema(options: SchemaClassOptions = {}) {
     newClass[field] = schema[field];
   }
   return newClass;
+}
+
+export function RegisterSchema(options: SchemaClassOptions = {}) {
+  return function <T>(originalClass: ClassType<T>): any {
+    Metadata.set('SchemaClassOptions', options)(originalClass);
+    return SchemaClass(originalClass);
   };
 }