diff --git a/pkg/app/promise_proxy.go b/pkg/app/promise_proxy.go
index dfdb4b4..094df4d 100644
--- a/pkg/app/promise_proxy.go
+++ b/pkg/app/promise_proxy.go
@@ -46,11 +46,11 @@ func NewPromiseProxyFrom(rt *goja.Runtime) *PromiseProxy {
 	return NewPromiseProxy(promise, resolve, reject)
 }
 
-func IsPromise(v goja.Value) (*goja.Promise, bool) {
+func isPromise(v any) (*goja.Promise, bool) {
 	if v == nil {
 		return nil, false
 	}
 
-	promise, ok := v.Export().(*goja.Promise)
+	promise, ok := v.(*goja.Promise)
 	return promise, ok
 }
diff --git a/pkg/app/server.go b/pkg/app/server.go
index f14cf0b..4f40f8c 100644
--- a/pkg/app/server.go
+++ b/pkg/app/server.go
@@ -23,7 +23,7 @@ type Server struct {
 	modules   []ServerModule
 }
 
-func (s *Server) ExecFuncByName(ctx context.Context, funcName string, args ...interface{}) (any, error) {
+func (s *Server) ExecFuncByName(ctx context.Context, funcName string, args ...any) (any, error) {
 	ctx = logger.With(ctx, logger.F("function", funcName), logger.F("args", args))
 
 	ret, err := s.Exec(ctx, funcName, args...)
@@ -34,9 +34,9 @@ func (s *Server) ExecFuncByName(ctx context.Context, funcName string, args ...in
 	return ret, nil
 }
 
-func (s *Server) Exec(ctx context.Context, callableOrFuncname any, args ...interface{}) (any, error) {
+func (s *Server) Exec(ctx context.Context, callableOrFuncname any, args ...any) (any, error) {
 	type result struct {
-		value goja.Value
+		value any
 		err   error
 	}
 
@@ -110,7 +110,7 @@ func (s *Server) Exec(ctx context.Context, callableOrFuncname any, args ...inter
 		}
 
 		done <- result{
-			value: value,
+			value: value.Export(),
 		}
 
 		logger.Debug(ctx, "executed callable", logger.F("callable", callableOrFuncname), logger.F("duration", time.Since(start).String()))
@@ -129,13 +129,11 @@ func (s *Server) Exec(ctx context.Context, callableOrFuncname any, args ...inter
 			return nil, errors.WithStack(result.err)
 		}
 
-		value := result.value
-
-		if promise, ok := IsPromise(value); ok {
+		if promise, ok := isPromise(result.value); ok {
 			return s.waitForPromise(promise), nil
 		}
 
-		return value.Export(), nil
+		return result.value, nil
 	}
 }