diff --git a/lib/queryTransform.js b/lib/queryTransform.js
index e1aabc9..950c4b4 100644
--- a/lib/queryTransform.js
+++ b/lib/queryTransform.js
@@ -30,7 +30,9 @@ module.exports = function(query) {
 
     var select = {};
     for (var key in query.$select || []) {
-        select[query.$select[key]] = 1;
+        if(query.$select){
+            select[query.$select[key]] = 1;
+        }
     }
     query.$select=  select;