diff --git a/src/common/Mapper.ts b/src/common/Mapper.ts
index 2b46502b78..42c0c7f568 100644
--- a/src/common/Mapper.ts
+++ b/src/common/Mapper.ts
@@ -16,7 +16,7 @@ export function mapArray<T>(value: T[] | undefined, clazz?: Callable<T>): T[] {
 }
 
 function mapInternal<T>(value: any, clazz?: Callable<T>): T {
-  if (!value) {
+  if (!!value) {
     return value;
   }