diff --git a/packages/core/aqua-to-js-compiler/src/generate/service.ts b/packages/core/aqua-to-js-compiler/src/generate/service.ts
index e52cf6b2..6653148d 100644
--- a/packages/core/aqua-to-js-compiler/src/generate/service.ts
+++ b/packages/core/aqua-to-js-compiler/src/generate/service.ts
@@ -18,10 +18,6 @@ import { ServiceDef } from '@fluencelabs/interfaces';
 import { recursiveRenameLaquaProps } from '../utils.js';
 import { TypeGenerator } from './interfaces.js';
 
-interface DefaultServiceId {
-    s_Some__f_value?: string
-}
-
 export class ServiceGenerator {
     constructor(
         private typeGenerator: TypeGenerator
@@ -54,8 +50,8 @@ export class ServiceGenerator {
     private serviceToJson(service: ServiceDef): string {
         return JSON.stringify({
             ...(
-                (service.defaultServiceId as DefaultServiceId)?.s_Some__f_value
-                    ? { defaultServiceId: (service.defaultServiceId as DefaultServiceId).s_Some__f_value }
+                service.defaultServiceId.s_Some__f_value
+                    ? { defaultServiceId: service.defaultServiceId.s_Some__f_value }
                     : {}
             ),
             functions: recursiveRenameLaquaProps(service.functions)
diff --git a/packages/core/interfaces/src/compilerSupport/aquaTypeDefinitions.ts b/packages/core/interfaces/src/compilerSupport/aquaTypeDefinitions.ts
index ac59ed91..0e215d92 100644
--- a/packages/core/interfaces/src/compilerSupport/aquaTypeDefinitions.ts
+++ b/packages/core/interfaces/src/compilerSupport/aquaTypeDefinitions.ts
@@ -229,7 +229,9 @@ export interface ServiceDef {
     /**
      * Default service id. If the service has no default id the value should be undefined
      */
-    defaultServiceId?: {};
+    defaultServiceId: {
+        s_Some__f_value?: string
+    };
 
     /**
      * List of functions which the service consists of