diff --git a/lib/readline.js b/lib/readline.js
index 515dd08d45f..60e0f074107 100644
--- a/lib/readline.js
+++ b/lib/readline.js
@@ -40,7 +40,7 @@ function Interface (output, completer) {
 
   this.setPrompt("> ");
 
-  this.enabled = output.fd < 3;  // Looks like a TTY.
+  this.enabled = stdio.isatty(output.fd);
 
   if (parseInt(process.env['NODE_NO_READLINE'], 10)) {
     this.enabled = false;
diff --git a/test/simple/test-readline.js b/test/disabled/test-readline.js
similarity index 95%
rename from test/simple/test-readline.js
rename to test/disabled/test-readline.js
index edc830fe124..1ed935e84af 100644
--- a/test/simple/test-readline.js
+++ b/test/disabled/test-readline.js
@@ -1,3 +1,5 @@
+// Can't test this when 'make test' doesn't assign a tty to the stdout.
+// Yet another use-case for require('tty').spawn ?
 common = require("../common");
 assert = common.assert;
 var readline = require("readline");