diff --git a/src/node_buffer.cc b/src/node_buffer.cc
index 75bac2a2808..33870c3757a 100644
--- a/src/node_buffer.cc
+++ b/src/node_buffer.cc
@@ -679,6 +679,11 @@ Handle<Value> Buffer::ByteLength(const Arguments &args) {
 Handle<Value> Buffer::MakeFastBuffer(const Arguments &args) {
   HandleScope scope;
 
+  if (!Buffer::HasInstance(args[0])) {
+    return ThrowException(Exception::TypeError(String::New(
+            "First argument must be a Buffer")));
+  }
+
   Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args[0]->ToObject());
   Local<Object> fast_buffer = args[1]->ToObject();;
   uint32_t offset = args[2]->Uint32Value();
diff --git a/test/simple/test-buffer.js b/test/simple/test-buffer.js
index 1aa4611010d..ae67d09d6ed 100644
--- a/test/simple/test-buffer.js
+++ b/test/simple/test-buffer.js
@@ -520,3 +520,7 @@ assert.equal(0xee, b[0]);
 assert.equal(0xad, b[1]);
 assert.equal(0xbe, b[2]);
 assert.equal(0xef, b[3]);
+
+
+// This should not segfault the program.
+new Buffer('"pong"', 0, 6, 8031, '127.0.0.1')