diff --git a/lib/output.js b/lib/output.js
index ab9b82b4e57..b33bc63408c 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -520,6 +520,12 @@ function OutputStream(options) {
             return true;
     });
 
+    PARENS(AST_NaN, function(output){
+        var p = output.parent();
+        if (p instanceof AST_PropAccess && p.expression === this)
+            return true;
+    });
+
     function assign_and_conditional_paren_rules(output) {
         var p = output.parent();
         // !(a = false) → true