diff --git a/lib/repl.js b/lib/repl.js
index 7b2c4d44d9..ee7dd9b61c 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -10,6 +10,8 @@ var scopeFunc = /^\s*function\s*([_\w\$]+)/;
 
 exports.scope = {};
 exports.prompt = "node> ";
+// Can overridden with custom print functions, such as `probe` or `eyes.js`
+exports.writer = sys.p;
 exports.start = function (prompt) {
   if (prompt !== undefined) {
     exports.prompt = prompt;
@@ -46,7 +48,7 @@ function readline (cmd) {
         var ret = eval(buffered_cmd);
         if (ret !== undefined) {
           exports.scope['_'] = ret;
-          sys.p(ret);
+          exports.writer(ret);
         }
       }