diff --git a/lib/parse.js b/lib/parse.js
index 7a6089e4..c042a60b 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -1276,11 +1276,11 @@ function parse($TEXT, options) {
               case "(":
                 next();
                 var ex = expression(true);
-                var orig_len = start.comments_before.length;
-                start.comments_before.orig_len = orig_len;
-                [].push.apply(start.comments_before, ex.start.comments_before);
-                ex.start.comments_before = start.comments_before;
-                if (orig_len == 0 && start.comments_before.length > 0) {
+                var len = start.comments_before.length;
+                [].unshift.apply(ex.start.comments_before, start.comments_before);
+                start.comments_before = ex.start.comments_before;
+                start.comments_before_length = len;
+                if (len == 0 && start.comments_before.length > 0) {
                     var comment = start.comments_before[0];
                     if (!comment.nlb) {
                         comment.nlb = start.nlb;
@@ -1444,8 +1444,9 @@ function parse($TEXT, options) {
     };
 
     function mark_pure(call) {
-        var comments = call.start.comments_before;
-        var i = HOP(comments, "orig_len") ? comments.orig_len : comments.length;
+        var start = call.start;
+        var comments = start.comments_before;
+        var i = HOP(start, "comments_before_length") ? start.comments_before_length : comments.length;
         while (--i >= 0) {
             var comment = comments[i];
             if (/[@#]__PURE__/.test(comment.value)) {