diff --git a/openssl/src/bio/mod.rs b/openssl/src/bio/mod.rs
index 2f12f906..6229a5ec 100644
--- a/openssl/src/bio/mod.rs
+++ b/openssl/src/bio/mod.rs
@@ -1,7 +1,9 @@
 use libc::{c_void, c_int};
-use std::old_io::{EndOfFile, IoResult, IoError, OtherIoError};
-use std::old_io::{Reader, Writer};
+use std::io;
+use std::io::prelude::*;
 use std::ptr;
+use std::cmp;
+use std::num::Int;
 
 use ffi;
 use ssl::error::{SslError};
@@ -57,49 +59,45 @@ impl MemBio {
     }
 }
 
-impl Reader for MemBio {
-    fn read(&mut self, buf: &mut [u8]) -> IoResult<usize> {
+impl Read for MemBio {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        let len = cmp::min(<c_int as Int>::max_value() as usize, buf.len()) as c_int;
         let ret = unsafe {
-            ffi::BIO_read(self.bio, buf.as_ptr() as *mut c_void,
-                          buf.len() as c_int)
+            ffi::BIO_read(self.bio, buf.as_ptr() as *mut c_void, len)
         };
 
         if ret <= 0 {
             let is_eof = unsafe { ffi::BIO_eof(self.bio) };
-            let err = if is_eof {
-                IoError {
-                    kind: EndOfFile,
-                    desc: "MemBio EOF",
-                    detail: None
-                }
+            if is_eof {
+                Ok(0)
             } else {
-                IoError {
-                    kind: OtherIoError,
-                    desc: "MemBio read error",
-                    detail: Some(format!("{:?}", SslError::get()))
-                }
-            };
-            Err(err)
+                Err(io::Error::new(io::ErrorKind::Other,
+                                   "MemBio read error",
+                                   Some(format!("{:?}", SslError::get()))))
+            }
         } else {
             Ok(ret as usize)
         }
     }
 }
 
-impl Writer for MemBio {
-    fn write_all(&mut self, buf: &[u8]) -> IoResult<()> {
+impl Write for MemBio {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        let len = cmp::min(<c_int as Int>::max_value() as usize, buf.len()) as c_int;
         let ret = unsafe {
-            ffi::BIO_write(self.bio, buf.as_ptr() as *const c_void,
-                           buf.len() as c_int)
+            ffi::BIO_write(self.bio, buf.as_ptr() as *const c_void, len)
         };
-        if buf.len() != ret as usize {
-            Err(IoError {
-                kind: OtherIoError,
-                desc: "MemBio write error",
-                detail: Some(format!("{:?}", SslError::get()))
-            })
+
+        if ret < 0 {
+                Err(io::Error::new(io::ErrorKind::Other,
+                                   "MemBio write error",
+                                   Some(format!("{:?}", SslError::get()))))
         } else {
-            Ok(())
+            Ok(ret as usize)
         }
     }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
 }
diff --git a/openssl/src/crypto/hash.rs b/openssl/src/crypto/hash.rs
index f81532c9..29e180e5 100644
--- a/openssl/src/crypto/hash.rs
+++ b/openssl/src/crypto/hash.rs
@@ -1,6 +1,7 @@
 use libc::c_uint;
 use std::iter::repeat;
-use std::old_io::{IoError, Writer};
+use std::io::prelude::*;
+use std::io;
 
 use ffi;
 
@@ -73,10 +74,10 @@ use self::State::*;
 /// assert_eq!(res, spec);
 /// ```
 ///
-/// Use the `Writer` trait to supply the input in chunks.
+/// Use the `Write` trait to supply the input in chunks.
 ///
 /// ```
-/// use std::old_io::Writer;
+/// use std::io::prelude::*;
 /// use openssl::crypto::hash::{Hasher, Type};
 /// let data = [b"\x42\xF4", b"\x97\xE0"];
 /// let spec = b"\x7c\x43\x0f\x17\x8a\xef\xdf\x14\x87\xfe\xe7\x14\x4e\x96\x41\xe2";
@@ -168,10 +169,14 @@ impl Hasher {
     }
 }
 
-impl Writer for Hasher {
+impl Write for Hasher {
     #[inline]
-    fn write_all(&mut self, buf: &[u8]) -> Result<(), IoError> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         self.update(buf);
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
         Ok(())
     }
 }
@@ -213,7 +218,7 @@ pub fn hash(t: Type, data: &[u8]) -> Vec<u8> {
 mod tests {
     use serialize::hex::{FromHex, ToHex};
     use super::{hash, Hasher, Type};
-    use std::old_io::Writer;
+    use std::io::prelude::*;
 
     fn hash_test(hashtype: Type, hashtest: &(&str, &str)) {
         let res = hash(hashtype, &*hashtest.0.from_hex().unwrap());
diff --git a/openssl/src/crypto/hmac.rs b/openssl/src/crypto/hmac.rs
index 55007ceb..01874aec 100644
--- a/openssl/src/crypto/hmac.rs
+++ b/openssl/src/crypto/hmac.rs
@@ -16,7 +16,8 @@
 
 use libc::{c_int, c_uint};
 use std::iter::repeat;
-use std::old_io::{IoError, Writer};
+use std::io;
+use std::io::prelude::*;
 
 use crypto::hash::Type;
 use ffi;
@@ -46,10 +47,10 @@ use self::State::*;
 /// assert_eq!(spec, res);
 /// ```
 ///
-/// Use the `Writer` trait to supply the input in chunks.
+/// Use the `Write` trait to supply the input in chunks.
 ///
 /// ```
-/// use std::old_io::Writer;
+/// use std::io::prelude::*;
 /// use openssl::crypto::hash::Type;
 /// use openssl::crypto::hmac::HMAC;
 /// let key = b"Jefe";
@@ -150,10 +151,14 @@ impl HMAC {
     }
 }
 
-impl Writer for HMAC {
+impl Write for HMAC {
     #[inline]
-    fn write_all(&mut self, buf: &[u8]) -> Result<(), IoError> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         self.update(buf);
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
         Ok(())
     }
 }
@@ -197,7 +202,7 @@ mod tests {
     use crypto::hash::Type;
     use crypto::hash::Type::*;
     use super::{hmac, HMAC};
-    use std::old_io::Writer;
+    use std::io::prelude::*;
 
     fn test_hmac(ty: Type, tests: &[(Vec<u8>, Vec<u8>, Vec<u8>)]) {
         for &(ref key, ref data, ref res) in tests.iter() {
diff --git a/openssl/src/crypto/pkey.rs b/openssl/src/crypto/pkey.rs
index c20fae4f..ac910e0b 100644
--- a/openssl/src/crypto/pkey.rs
+++ b/openssl/src/crypto/pkey.rs
@@ -1,4 +1,5 @@
 use libc::{c_int, c_uint, c_ulong};
+use std::io::prelude::*;
 use std::iter::repeat;
 use std::mem;
 use std::ptr;
@@ -142,15 +143,16 @@ impl PKey {
 
     /// Stores private key as a PEM
     // FIXME: also add password and encryption
-    pub fn write_pem(&self, writer: &mut Writer/*, password: Option<String>*/) -> Result<(), SslError> {
+    pub fn write_pem<W: Write>(&self, writer: &mut W/*, password: Option<String>*/) -> Result<(), SslError> {
         let mut mem_bio = try!(MemBio::new());
         unsafe {
             try_ssl!(ffi::PEM_write_bio_PrivateKey(mem_bio.get_handle(), self.evp, ptr::null(),
                                                    ptr::null_mut(), -1, None, ptr::null_mut()));
 
         }
-        let buf = try!(mem_bio.read_to_end().map_err(StreamError));
-        writer.write_all(buf.as_slice()).map_err(StreamError)
+        let mut buf = vec![];
+        try!(mem_bio.read_to_end(&mut buf).map_err(StreamError));
+        writer.write_all(&buf).map_err(StreamError)
     }
 
     /**
diff --git a/openssl/src/lib.rs b/openssl/src/lib.rs
index 56720ae2..6f9d07d8 100644
--- a/openssl/src/lib.rs
+++ b/openssl/src/lib.rs
@@ -1,4 +1,5 @@
-#![feature(unsafe_destructor, core, old_io, std_misc, old_path)]
+#![feature(unsafe_destructor, core, io, std_misc, path, os)]
+#![cfg_attr(test, feature(net, fs))]
 #![doc(html_root_url="https://sfackler.github.io/rust-openssl/doc/openssl")]
 
 extern crate libc;
diff --git a/openssl/src/ssl/error.rs b/openssl/src/ssl/error.rs
index bb2a5557..81f38692 100644
--- a/openssl/src/ssl/error.rs
+++ b/openssl/src/ssl/error.rs
@@ -5,7 +5,7 @@ use libc::c_ulong;
 use std::error;
 use std::fmt;
 use std::ffi::CStr;
-use std::old_io::IoError;
+use std::io;
 
 use ffi;
 
@@ -13,7 +13,7 @@ use ffi;
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum SslError {
     /// The underlying stream reported an error
-    StreamError(IoError),
+    StreamError(io::Error),
     /// The SSL session has been closed by the other end
     SslSessionClosed,
     /// An error in the OpenSSL library
diff --git a/openssl/src/ssl/mod.rs b/openssl/src/ssl/mod.rs
index 5d3549ff..ecf12905 100644
--- a/openssl/src/ssl/mod.rs
+++ b/openssl/src/ssl/mod.rs
@@ -1,11 +1,17 @@
 use libc::{c_int, c_void, c_long};
 use std::ffi::{CStr, CString};
-use std::old_io::{IoResult, IoError, EndOfFile, OtherIoError, Stream, Reader, Writer};
-use std::mem;
 use std::fmt;
+use std::io;
+use std::io::prelude::*;
+use std::ffi::AsOsStr;
+use std::mem;
 use std::num::FromPrimitive;
+use std::num::Int;
+use std::path::Path;
 use std::ptr;
 use std::sync::{Once, ONCE_INIT, Arc};
+use std::ops::{Deref, DerefMut};
+use std::cmp;
 
 use bio::{MemBio};
 use ffi;
@@ -245,9 +251,9 @@ impl SslContext {
     #[allow(non_snake_case)]
     /// Specifies the file that contains trusted CA certificates.
     pub fn set_CA_file(&mut self, file: &Path) -> Option<SslError> {
+        let file = CString::new(file.as_os_str().to_str().expect("invalid utf8")).unwrap();
         wrap_ssl_result(
             unsafe {
-                let file = CString::new(file.as_vec()).unwrap();
                 ffi::SSL_CTX_load_verify_locations(*self.ctx, file.as_ptr(), ptr::null())
             })
     }
@@ -255,9 +261,9 @@ impl SslContext {
     /// Specifies the file that contains certificate
     pub fn set_certificate_file(&mut self, file: &Path,
                                 file_type: X509FileType) -> Option<SslError> {
+        let file = CString::new(file.as_os_str().to_str().expect("invalid utf8")).unwrap();
         wrap_ssl_result(
             unsafe {
-                let file = CString::new(file.as_vec()).unwrap();
                 ffi::SSL_CTX_use_certificate_file(*self.ctx, file.as_ptr(), file_type as c_int)
             })
     }
@@ -265,9 +271,9 @@ impl SslContext {
     /// Specifies the file that contains private key
     pub fn set_private_key_file(&mut self, file: &Path,
                                 file_type: X509FileType) -> Option<SslError> {
+        let file = CString::new(file.as_os_str().to_str().expect("invalid utf8")).unwrap();
         wrap_ssl_result(
             unsafe {
-                let file = CString::new(file.as_vec()).unwrap();
                 ffi::SSL_CTX_use_PrivateKey_file(*self.ctx, file.as_ptr(), file_type as c_int)
             })
     }
@@ -287,13 +293,17 @@ struct MemBioRef<'ssl> {
     bio: MemBio,
 }
 
-impl<'ssl> MemBioRef<'ssl> {
-    fn read(&mut self, buf: &mut [u8]) -> Option<usize> {
-        (&mut self.bio as &mut Reader).read(buf).ok()
-    }
+impl<'ssl> Deref for MemBioRef<'ssl> {
+    type Target = MemBio;
 
-    fn write_all(&mut self, buf: &[u8]) {
-        let _ = (&mut self.bio as &mut Writer).write_all(buf);
+    fn deref(&self) -> &MemBio {
+        &self.bio
+    }
+}
+
+impl<'ssl> DerefMut for MemBioRef<'ssl> {
+    fn deref_mut(&mut self) -> &mut MemBio {
+        &mut self.bio
     }
 }
 
@@ -354,13 +364,13 @@ impl Ssl {
     }
 
     fn read(&self, buf: &mut [u8]) -> c_int {
-        unsafe { ffi::SSL_read(*self.ssl, buf.as_ptr() as *mut c_void,
-                               buf.len() as c_int) }
+        let len = cmp::min(<c_int as Int>::max_value() as usize, buf.len()) as c_int;
+        unsafe { ffi::SSL_read(*self.ssl, buf.as_ptr() as *mut c_void, len) }
     }
 
     fn write(&self, buf: &[u8]) -> c_int {
-        unsafe { ffi::SSL_write(*self.ssl, buf.as_ptr() as *const c_void,
-                                buf.len() as c_int) }
+        let len = cmp::min(<c_int as Int>::max_value() as usize, buf.len()) as c_int;
+        unsafe { ffi::SSL_write(*self.ssl, buf.as_ptr() as *const c_void, len) }
     }
 
     fn get_error(&self, ret: c_int) -> LibSslError {
@@ -433,7 +443,7 @@ impl<S> fmt::Debug for SslStream<S> where S: fmt::Debug {
     }
 }
 
-impl<S: Stream> SslStream<S> {
+impl<S: Read+Write> SslStream<S> {
     fn new_base(ssl:Ssl, stream: S) -> SslStream<S> {
         SslStream {
             stream: stream,
@@ -507,11 +517,15 @@ impl<S: Stream> SslStream<S> {
                 return Ok(ret);
             }
 
-            match self.ssl.get_error(ret) {
+            let e = self.ssl.get_error(ret);
+            match e {
                 LibSslError::ErrorWantRead => {
                     try_ssl_stream!(self.flush());
                     let len = try_ssl_stream!(self.stream.read(self.buf.as_mut_slice()));
-                    self.ssl.get_rbio().write_all(&self.buf[..len]);
+                    if len == 0 {
+                        return Ok(0);
+                    }
+                    try_ssl_stream!(self.ssl.get_rbio().write_all(&self.buf[..len]));
                 }
                 LibSslError::ErrorWantWrite => { try_ssl_stream!(self.flush()) }
                 LibSslError::ErrorZeroReturn => return Err(SslSessionClosed),
@@ -521,14 +535,8 @@ impl<S: Stream> SslStream<S> {
         }
     }
 
-    fn write_through(&mut self) -> IoResult<()> {
-        loop {
-            match self.ssl.get_wbio().read(self.buf.as_mut_slice()) {
-                Some(len) => try!(self.stream.write_all(&self.buf[..len])),
-                None => break
-            };
-        }
-        Ok(())
+    fn write_through(&mut self) -> io::Result<()> {
+        io::copy(&mut *self.ssl.get_wbio(), &mut self.stream).map(|_| ())
     }
 
     /// Get the compression currently in use.  The result will be
@@ -549,56 +557,32 @@ impl<S: Stream> SslStream<S> {
     }
 }
 
-impl<S: Stream> Reader for SslStream<S> {
-    fn read(&mut self, buf: &mut [u8]) -> IoResult<usize> {
+impl<S: Read+Write> Read for SslStream<S> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         match self.in_retry_wrapper(|ssl| { ssl.read(buf) }) {
             Ok(len) => Ok(len as usize),
-            Err(SslSessionClosed) => {
-                Err(IoError {
-                    kind: EndOfFile,
-                    desc: "SSL session closed",
-                    detail: None
-                })
-            }
+            Err(SslSessionClosed) => Ok(0),
             Err(StreamError(e)) => Err(e),
             Err(e @ OpenSslErrors(_)) => {
-                Err(IoError {
-                    kind: OtherIoError,
-                    desc: "OpenSSL error",
-                    detail: Some(format!("{}", e)),
-                })
+                Err(io::Error::new(io::ErrorKind::Other, "OpenSSL error", Some(format!("{}", e))))
             }
         }
     }
 }
 
-impl<S: Stream> Writer for SslStream<S> {
-    fn write_all(&mut self, mut buf: &[u8]) -> IoResult<()> {
-        while !buf.is_empty() {
-            match self.in_retry_wrapper(|ssl| ssl.write(buf)) {
-                Ok(len) => buf = &buf[len as usize..],
-                Err(SslSessionClosed) => {
-                    return Err(IoError {
-                        kind: EndOfFile,
-                        desc: "SSL session closed",
-                        detail: None,
-                    });
-                }
-                Err(StreamError(e)) => return Err(e),
-                Err(e @ OpenSslErrors(_)) => {
-                    return Err(IoError {
-                        kind: OtherIoError,
-                        desc: "OpenSSL error",
-                        detail: Some(format!("{}", e)),
-                    });
-                }
+impl<S: Read+Write> Write for SslStream<S> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        match self.in_retry_wrapper(|ssl| ssl.write(buf)) {
+            Ok(len) => Ok(len as usize),
+            Err(SslSessionClosed) => Ok(0),
+            Err(StreamError(e)) => return Err(e),
+            Err(e @ OpenSslErrors(_)) => {
+                Err(io::Error::new(io::ErrorKind::Other, "OpenSSL error", Some(format!("{}", e))))
             }
-            try!(self.write_through());
         }
-        Ok(())
     }
 
-    fn flush(&mut self) -> IoResult<()> {
+    fn flush(&mut self) -> io::Result<()> {
         try!(self.write_through());
         self.stream.flush()
     }
@@ -606,15 +590,15 @@ impl<S: Stream> Writer for SslStream<S> {
 
 /// A utility type to help in cases where the use of SSL is decided at runtime.
 #[derive(Debug)]
-pub enum MaybeSslStream<S> where S: Stream {
+pub enum MaybeSslStream<S> where S: Read+Write {
     /// A connection using SSL
     Ssl(SslStream<S>),
     /// A connection not using SSL
     Normal(S),
 }
 
-impl<S> Reader for MaybeSslStream<S> where S: Stream {
-    fn read(&mut self, buf: &mut [u8]) -> IoResult<usize> {
+impl<S> Read for MaybeSslStream<S> where S: Read+Write {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
         match *self {
             MaybeSslStream::Ssl(ref mut s) => s.read(buf),
             MaybeSslStream::Normal(ref mut s) => s.read(buf),
@@ -622,15 +606,15 @@ impl<S> Reader for MaybeSslStream<S> where S: Stream {
     }
 }
 
-impl<S> Writer for MaybeSslStream<S> where S: Stream{
-    fn write_all(&mut self, buf: &[u8]) -> IoResult<()> {
+impl<S> Write for MaybeSslStream<S> where S: Read+Write {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
         match *self {
-            MaybeSslStream::Ssl(ref mut s) => s.write_all(buf),
-            MaybeSslStream::Normal(ref mut s) => s.write_all(buf),
+            MaybeSslStream::Ssl(ref mut s) => s.write(buf),
+            MaybeSslStream::Normal(ref mut s) => s.write(buf),
         }
     }
 
-    fn flush(&mut self) -> IoResult<()> {
+    fn flush(&mut self) -> io::Result<()> {
         match *self {
             MaybeSslStream::Ssl(ref mut s) => s.flush(),
             MaybeSslStream::Normal(ref mut s) => s.flush(),
@@ -638,7 +622,7 @@ impl<S> Writer for MaybeSslStream<S> where S: Stream{
     }
 }
 
-impl<S> MaybeSslStream<S> where S: Stream {
+impl<S> MaybeSslStream<S> where S: Read+Write {
     /// Returns a reference to the underlying stream.
     pub fn get_ref(&self) -> &S {
         match *self {
diff --git a/openssl/src/ssl/tests.rs b/openssl/src/ssl/tests.rs
index 4bb3c2ca..41e54baa 100644
--- a/openssl/src/ssl/tests.rs
+++ b/openssl/src/ssl/tests.rs
@@ -1,7 +1,8 @@
 use serialize::hex::FromHex;
-use std::old_io::net::tcp::TcpStream;
-use std::old_io::{Writer};
-use std::thread;
+use std::net::TcpStream;
+use std::io;
+use std::io::prelude::*;
+use std::path::Path;
 
 use crypto::hash::Type::{SHA256};
 use ssl::SslMethod::Sslv23;
@@ -191,17 +192,6 @@ fn test_read() {
     let mut stream = SslStream::new(&SslContext::new(Sslv23).unwrap(), stream).unwrap();
     stream.write_all("GET /\r\n\r\n".as_bytes()).unwrap();
     stream.flush().unwrap();
-    stream.read_to_end().ok().expect("read error");
-}
-
-#[test]
-fn test_clone() {
-    let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
-    let mut stream = SslStream::new(&SslContext::new(Sslv23).unwrap(), stream).unwrap();
-    let mut stream2 = stream.clone();
-    let _t = thread::spawn(move || {
-        stream2.write_all("GET /\r\n\r\n".as_bytes()).unwrap();
-        stream2.flush().unwrap();
-    });
-    stream.read_to_end().ok().expect("read error");
+    println!("written");
+    io::copy(&mut stream, &mut io::sink()).ok().expect("read error");
 }
diff --git a/openssl/src/x509/mod.rs b/openssl/src/x509/mod.rs
index 898ea633..97d3dbdb 100644
--- a/openssl/src/x509/mod.rs
+++ b/openssl/src/x509/mod.rs
@@ -1,4 +1,6 @@
 use libc::{c_char, c_int, c_long, c_uint};
+use std::io;
+use std::io::prelude::*;
 use std::cmp::Ordering;
 use std::ffi::CString;
 use std::iter::repeat;
@@ -150,8 +152,10 @@ impl<'a, T: AsStr<'a>> ToStr for Vec<T> {
 /// ```
 /// # #[allow(unstable)]
 /// # fn main() {
-/// use std::old_io::{File, Open, Write};
-/// # use std::old_io::fs;
+/// use std::fs;
+/// use std::fs::File;
+/// use std::io::prelude::*;
+/// use std::path::Path;
 ///
 /// use openssl::crypto::hash::Type;
 /// use openssl::x509::{KeyUsage, X509Generator};
@@ -165,15 +169,15 @@ impl<'a, T: AsStr<'a>> ToStr for Vec<T> {
 ///
 /// let (cert, pkey) = gen.generate().unwrap();
 ///
-/// let cert_path = Path::new("doc_cert.pem");
-/// let mut file = File::open_mode(&cert_path, Open, Write).unwrap();
+/// let cert_path = "doc_cert.pem";
+/// let mut file = File::create(cert_path).unwrap();
 /// assert!(cert.write_pem(&mut file).is_ok());
-/// # let _ = fs::unlink(&cert_path);
+/// # let _ = fs::remove_file(cert_path);
 ///
-/// let pkey_path = Path::new("doc_key.pem");
-/// let mut file = File::open_mode(&pkey_path, Open, Write).unwrap();
+/// let pkey_path = "doc_key.pem";
+/// let mut file = File::create(pkey_path).unwrap();
 /// assert!(pkey.write_pem(&mut file).is_ok());
-/// # let _ = fs::unlink(&pkey_path);
+/// # let _ = fs::remove_file(pkey_path);
 /// # }
 /// ```
 pub struct X509Generator {
@@ -369,10 +373,9 @@ impl<'ctx> X509<'ctx> {
     }
 
     /// Reads certificate from PEM, takes ownership of handle
-    pub fn from_pem<R>(reader: &mut R) -> Result<X509<'ctx>, SslError> where R: Reader {
+    pub fn from_pem<R>(reader: &mut R) -> Result<X509<'ctx>, SslError> where R: Read {
         let mut mem_bio = try!(MemBio::new());
-        let buf = try!(reader.read_to_end().map_err(StreamError));
-        try!(mem_bio.write_all(buf.as_slice()).map_err(StreamError));
+        try!(io::copy(reader, &mut mem_bio).map_err(StreamError));
 
         unsafe {
             let handle = try_ssl_null!(ffi::PEM_read_bio_X509(mem_bio.get_handle(),
@@ -412,14 +415,13 @@ impl<'ctx> X509<'ctx> {
     }
 
     /// Writes certificate as PEM
-    pub fn write_pem<W>(&self, writer: &mut W) -> Result<(), SslError> where W: Writer{
+    pub fn write_pem<W>(&self, writer: &mut W) -> Result<(), SslError> where W: Write {
         let mut mem_bio = try!(MemBio::new());
         unsafe {
             try_ssl!(ffi::PEM_write_bio_X509(mem_bio.get_handle(),
                                              self.handle));
         }
-        let buf = try!(mem_bio.read_to_end().map_err(StreamError));
-        writer.write_all(buf.as_slice()).map_err(StreamError)
+        io::copy(&mut mem_bio, writer).map_err(StreamError).map(|_| ())
     }
 }
 
diff --git a/openssl/src/x509/tests.rs b/openssl/src/x509/tests.rs
index 4f24e70c..cbb3d902 100644
--- a/openssl/src/x509/tests.rs
+++ b/openssl/src/x509/tests.rs
@@ -1,6 +1,7 @@
 use serialize::hex::FromHex;
-use std::old_io::{File, Open, Read};
-use std::old_io::util::NullWriter;
+use std::io;
+use std::path::Path;
+use std::fs::File;
 
 use crypto::hash::Type::{SHA256};
 use x509::{X509, X509Generator};
@@ -22,9 +23,8 @@ fn test_cert_gen() {
 
     let (cert, pkey) = res.unwrap();
 
-    let mut writer = NullWriter;
-    assert!(cert.write_pem(&mut writer).is_ok());
-    assert!(pkey.write_pem(&mut writer).is_ok());
+    assert!(cert.write_pem(&mut io::sink()).is_ok());
+    assert!(pkey.write_pem(&mut io::sink()).is_ok());
 
     // FIXME: check data in result to be correct, needs implementation
     // of X509 getters
@@ -33,7 +33,7 @@ fn test_cert_gen() {
 #[test]
 fn test_cert_loading() {
     let cert_path = Path::new("test/cert.pem");
-    let mut file = File::open_mode(&cert_path, Open, Read)
+    let mut file = File::open(&cert_path)
         .ok()
         .expect("Failed to open `test/cert.pem`");