diff --git a/lib/buffer.js b/lib/buffer.js
index ccd899da5f32ae..07e533b1ce0f6d 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -335,6 +335,14 @@ Buffer.byteLength = byteLength;
 
 // toString(encoding, start=0, end=buffer.length)
 Buffer.prototype.toString = function(encoding, start, end) {
+  // .toString() can be called by JS on prototype (Buffer.prototype + '').
+  if (!(this instanceof Buffer)) {
+    if (arguments.length === 0)
+      return Object.prototype.toString.call(this);
+    else
+      throw new TypeError('this must be instance of Buffer');
+  }
+
   var loweredCase = false;
 
   start = start >>> 0;
diff --git a/test/parallel/test-buffer.js b/test/parallel/test-buffer.js
index 1d02148734e38a..b770c0a3da7df5 100644
--- a/test/parallel/test-buffer.js
+++ b/test/parallel/test-buffer.js
@@ -1172,3 +1172,7 @@ Buffer.poolSize = ps;
 assert.throws(function() {
   Buffer(10).copy();
 });
+
+// https://github.com/nodejs/io.js/issues/1485
+// C++ bindings fail assertions (die) when called on non-buffers.
+assert.equal(Buffer.prototype.toString(), '[object Object]');