diff --git a/compiler/cpp/src/generate/t_js_generator.cc b/compiler/cpp/src/generate/t_js_generator.cc
index 6cca3df..af66ade 100644
--- a/compiler/cpp/src/generate/t_js_generator.cc
+++ b/compiler/cpp/src/generate/t_js_generator.cc
@@ -2147,7 +2147,7 @@
   for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
     str += (*f_iter)->get_name() + ts_get_req(*f_iter) + ": " + ts_get_type((*f_iter)->get_type());
 
-    if (f_iter + 1 != fields.end() || include_callback) {
+    if (f_iter + 1 != fields.end() || (include_callback && fields.size() > 0)) {
       str += ", ";
     }
   }