diff --git a/lib/reporters/base.js b/lib/reporters/base.js
index 670a160fa8..b1d026fcce 100644
--- a/lib/reporters/base.js
+++ b/lib/reporters/base.js
@@ -25,7 +25,7 @@ exports = module.exports = Base;
  * Check if both stdio streams are associated with a tty.
  */
 
-var isatty = tty.isatty(1) && tty.isatty(2);
+var isatty = process.stdout.isTTY && process.stderr.isTTY;
 
 /**
  * Save log references to avoid tests interfering (see GH-3604).