diff --git a/lib/output.js b/lib/output.js
index cb743bd6..e539bc1b 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -1068,7 +1068,10 @@ function OutputStream(options) {
             // the space is optional depending on "beautify"
             output.space();
         }
+        var isYield = (self.right.operator == "yield" || self.right.operator === "yield*");
+        isYield && output.print("(");
         self.right.print(output);
+        isYield && output.print(")");
     });
     DEFPRINT(AST_Conditional, function(self, output){
         self.condition.print(output);