diff --git a/utils/shell-config.js b/utils/shell-config.js
index 8b2c6da9..59d7895c 100644
--- a/utils/shell-config.js
+++ b/utils/shell-config.js
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2018 Apple Inc. All rights reserved.
+ * Copyright (C) 2018-2025 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -27,10 +27,10 @@ const isInBrowser = false;
 if (typeof console == "undefined")
     console = {};
 
-console.debug ??= (...args) => console.log("Debug:", ...args);
+console.debug ??= (...args) => printErr("Debug: " + args.join(" "));
 console.log ??= (...args) => print(args.join(" "));
-console.warn ??= (...args) => console.log("Warn:", ...args);
-console.error ??= (...args) => console.log("Error:", ...args); 
+console.warn ??= (...args) => printErr("Warn: " + args.join(" "));
+console.error ??= (...args) => printErr("Error: " + args.join(" "));
 console.assert ??=  (condition, message) => {
     if (!condition)
         throw new Error(`Assertion failed: ${message}`);