diff --git a/lib/buffer.js b/lib/buffer.js
index 6514d0eb6dcf5d..881bdc2e1183d1 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -477,10 +477,14 @@ function slowIndexOf(buffer, val, byteOffset, encoding) {
 }
 
 Buffer.prototype.indexOf = function indexOf(val, byteOffset, encoding) {
-  if (byteOffset > 0x7fffffff)
+  if (typeof byteOffset === 'string') {
+    encoding = byteOffset;
+    byteOffset = 0;
+  } else if (byteOffset > 0x7fffffff) {
     byteOffset = 0x7fffffff;
-  else if (byteOffset < -0x80000000)
+  } else if (byteOffset < -0x80000000) {
     byteOffset = -0x80000000;
+  }
   byteOffset >>= 0;
 
   if (typeof val === 'string') {
diff --git a/test/parallel/test-buffer-indexof.js b/test/parallel/test-buffer-indexof.js
index aac5b18f718cb3..83776be80a37ee 100644
--- a/test/parallel/test-buffer-indexof.js
+++ b/test/parallel/test-buffer-indexof.js
@@ -111,6 +111,11 @@ assert.equal(
     .indexOf(Buffer('d', 'binary'), 0, 'binary'), 3);
 
 
+// test optional offset with passed encoding
+assert.equal(new Buffer('aaaa0').indexOf('30', 'hex'), 4);
+assert.equal(new Buffer('aaaa00a').indexOf('3030', 'hex'), 4);
+
+
 // test usc2 encoding
 var twoByteString = new Buffer('\u039a\u0391\u03a3\u03a3\u0395', 'ucs2');