diff --git a/static/js/trueTypeOf.js b/static/js/trueTypeOf.js
index eeec8d19..e5171ce4 100644
--- a/static/js/trueTypeOf.js
+++ b/static/js/trueTypeOf.js
@@ -1,3 +1,8 @@
 function trueTypeOf(object){
-  return object.constructor.name
+  if (object==null){
+    return "null"
+  }
+  else {
+   return object.constructor.name
+  }
 }