diff --git a/test/compress/issue-597.js b/test/compress/issue-597.js
index 3c651a4c..f243223a 100644
--- a/test/compress/issue-597.js
+++ b/test/compress/issue-597.js
@@ -6,7 +6,7 @@ NaN_and_Infinity_must_have_parens: {
     }
     expect: {
         (1/0).toString();
-        (0/0).toString();
+        NaN.toString();         // transformation to 0/0 dropped
     }
 }