diff --git a/lib/repl.js b/lib/repl.js
index 434ff66baeb..33794776727 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -105,7 +105,7 @@ function REPLServer(prompt, stream) {
   this.commands = {};
   defineDefaultCommands(this);
 
-  if (rli.enabled && !disableColors) {
+  if (rli.enabled && !disableColors && exports.writer === util.inspect) {
     // Turn on ANSI coloring.
     exports.writer = function(obj, showHidden, depth) {
       return util.inspect(obj, showHidden, depth, true);