diff --git a/compiler/cpp/src/generate/t_js_generator.cc b/compiler/cpp/src/generate/t_js_generator.cc
index d7d83bf..3d781a7 100644
--- a/compiler/cpp/src/generate/t_js_generator.cc
+++ b/compiler/cpp/src/generate/t_js_generator.cc
@@ -688,7 +688,7 @@
   indent(out) << "output.writeStructBegin('" << name << "');" << endl;
 
   for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {
-    out << indent() << "if (this." << (*f_iter)->get_name() << ") {" << endl;
+    out << indent() << "if (this." << (*f_iter)->get_name() << " != null) {" << endl;
     indent_up();
 
     indent(out) <<