diff --git a/spring-rest2ts-spring/src/main/java/com/blueveery/springrest2ts/implgens/FetchBasedImplementationGenerator.java b/spring-rest2ts-spring/src/main/java/com/blueveery/springrest2ts/implgens/FetchBasedImplementationGenerator.java
index 4ce855f..8e6c4be 100644
--- a/spring-rest2ts-spring/src/main/java/com/blueveery/springrest2ts/implgens/FetchBasedImplementationGenerator.java
+++ b/spring-rest2ts-spring/src/main/java/com/blueveery/springrest2ts/implgens/FetchBasedImplementationGenerator.java
@@ -159,15 +159,10 @@ public void changeMethodBeforeImplementationGeneration(TSMethod tsMethod) {
     @Override
     public TSType mapReturnType(TSMethod tsMethod, TSType tsType) {
         if (isRestClass(tsMethod.getOwner())) {
-            tsMethod.setAsync(useAsync);
-            if (useAsync) {
-                return tsType;
-            } else {
-                if (tsType == TypeMapper.tsVoid) {
-                    return new TSInterfaceReference(promiseInterface, responseInterface);
-                }
-                return new TSInterfaceReference(promiseInterface, tsType);
+            if (tsType == TypeMapper.tsVoid) {
+                return new TSInterfaceReference(promiseInterface, responseInterface);
             }
+            return new TSInterfaceReference(promiseInterface, tsType);
         }
         return tsType;
     }