diff --git a/lib/6to5/transform.js b/lib/6to5/transform.js
index 277333c665..749796bde2 100644
--- a/lib/6to5/transform.js
+++ b/lib/6to5/transform.js
@@ -22,7 +22,10 @@ transform.test = function (task, assert) {
   var exec   = task.exec;
 
   var getOpts = function (filename) {
-    return _.merge({ filename: filename }, opts);
+    return _.merge({
+      filename: filename,
+      whitespace: false
+    }, opts);
   };
 
   var execCode = exec.code.trim();
@@ -68,11 +71,10 @@ transform.test = function (task, assert) {
     var consumer = new sourceMap.SourceMapConsumer(result.map);
 
     _.each(task.sourceMappings, function (mapping, i) {
-      var gen  = mapping.generated;
-      var orig = mapping.original;
+      var expect = mapping.original;
 
-      var pos = consumer.originalPositionFor(gen);
-      assert.equal(pos.line + ":" + pos.column, orig.line + ":" + orig.column);
+      var actual = consumer.originalPositionFor(mapping.generated);
+      assert.equal(actual.line + ":" + actual.column, expect.line + ":" + expect.column);
     });
   }
 };