diff --git a/Cargo.toml b/Cargo.toml
index 41c0671..58ece24 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -25,5 +25,6 @@ webpki = "0.18.1"
 tokio = "0.1.6"
 
 [features]
-default = [ "tokio-support" ]
-tokio-support = [ "tokio", "bytes", "iovec" ]
+default = ["tokio-support"]
+nightly = ["bytes", "iovec"]
+tokio-support = ["tokio"]
diff --git a/src/common.rs b/src/common/mod.rs
similarity index 57%
rename from src/common.rs
rename to src/common/mod.rs
index 9e3cb5c..1f5d1d2 100644
--- a/src/common.rs
+++ b/src/common/mod.rs
@@ -1,11 +1,14 @@
-use std::cmp::{ self, Ordering };
-use std::io::{ self, Read, Write };
-use rustls::{ Session, WriteV };
-use tokio::prelude::Async;
-use tokio::io::AsyncWrite;
-use bytes::Buf;
-use iovec::IoVec;
+#[cfg(feature = "nightly")]
+#[cfg(feature = "tokio-support")]
+mod vecbuf;
 
+use std::io::{ self, Read, Write };
+use rustls::Session;
+#[cfg(feature = "nightly")]
+use rustls::WriteV;
+#[cfg(feature = "nightly")]
+#[cfg(feature = "tokio-support")]
+use tokio::io::AsyncWrite;
 
 pub struct Stream<'a, S: 'a, IO: 'a> {
     session: &'a mut S,
@@ -67,14 +70,27 @@ impl<'a, S: Session, IO: Read + Write> Stream<'a, S, IO> {
     }
 }
 
+#[cfg(not(feature = "nightly"))]
+impl<'a, S: Session, IO: Read + Write> WriteTls<'a, S, IO> for Stream<'a, S, IO> {
+    fn write_tls(&mut self) -> io::Result<usize> {
+        self.session.write_tls(self.io)
+    }
+}
+
+#[cfg(feature = "nightly")]
 impl<'a, S: Session, IO: Read + Write> WriteTls<'a, S, IO> for Stream<'a, S, IO> {
     default fn write_tls(&mut self) -> io::Result<usize> {
         self.session.write_tls(self.io)
     }
 }
 
+#[cfg(feature = "nightly")]
+#[cfg(feature = "tokio-support")]
 impl<'a, S: Session, IO: Read + AsyncWrite> WriteTls<'a, S, IO> for Stream<'a, S, IO> {
     fn write_tls(&mut self) -> io::Result<usize> {
+        use tokio::prelude::Async;
+        use self::vecbuf::VecBuf;
+
         struct V<'a, IO: 'a>(&'a mut IO);
 
         impl<'a, IO: AsyncWrite> WriteV for V<'a, IO> {
@@ -125,122 +141,3 @@ impl<'a, S: Session, IO: Read + Write> io::Write for Stream<'a, S, IO> {
         Ok(())
     }
 }
-
-
-struct VecBuf<'a, 'b: 'a> {
-    pos: usize,
-    cur: usize,
-    inner: &'a [&'b [u8]]
-}
-
-impl<'a, 'b> VecBuf<'a, 'b> {
-    fn new(vbytes: &'a [&'b [u8]]) -> Self {
-        VecBuf { pos: 0, cur: 0, inner: vbytes }
-    }
-}
-
-impl<'a, 'b> Buf for VecBuf<'a, 'b> {
-    fn remaining(&self) -> usize {
-        let sum = self.inner
-            .iter()
-            .skip(self.pos)
-            .map(|bytes| bytes.len())
-            .sum::<usize>();
-        sum - self.cur
-    }
-
-    fn bytes(&self) -> &[u8] {
-        &self.inner[self.pos][self.cur..]
-    }
-
-    fn advance(&mut self, cnt: usize) {
-        let current = self.inner[self.pos].len();
-        match (self.cur + cnt).cmp(&current) {
-            Ordering::Equal => if self.pos + 1 < self.inner.len() {
-                self.pos += 1;
-                self.cur = 0;
-            } else {
-                self.cur += cnt;
-            },
-            Ordering::Greater => {
-                if self.pos + 1 < self.inner.len() {
-                    self.pos += 1;
-                }
-                let remaining = self.cur + cnt - current;
-                self.advance(remaining);
-            },
-            Ordering::Less => self.cur += cnt,
-        }
-    }
-
-    fn bytes_vec<'c>(&'c self, dst: &mut [&'c IoVec]) -> usize {
-        let len = cmp::min(self.inner.len() - self.pos, dst.len());
-
-        if len > 0 {
-            dst[0] = self.bytes().into();
-        }
-
-        for i in 1..len {
-            dst[i] = self.inner[self.pos + i].into();
-        }
-
-        len
-    }
-}
-
-#[cfg(test)]
-mod test_vecbuf {
-    use super::*;
-
-    #[test]
-    fn test_fresh_cursor_vec() {
-        let mut buf = VecBuf::new(&[b"he", b"llo"]);
-
-        assert_eq!(buf.remaining(), 5);
-        assert_eq!(buf.bytes(), b"he");
-
-        buf.advance(2);
-
-        assert_eq!(buf.remaining(), 3);
-        assert_eq!(buf.bytes(), b"llo");
-
-        buf.advance(3);
-
-        assert_eq!(buf.remaining(), 0);
-        assert_eq!(buf.bytes(), b"");
-    }
-
-    #[test]
-    fn test_get_u8() {
-        let mut buf = VecBuf::new(&[b"\x21z", b"omg"]);
-        assert_eq!(0x21, buf.get_u8());
-    }
-
-    #[test]
-    fn test_get_u16() {
-        let mut buf = VecBuf::new(&[b"\x21\x54z", b"omg"]);
-        assert_eq!(0x2154, buf.get_u16_be());
-        let mut buf = VecBuf::new(&[b"\x21\x54z", b"omg"]);
-        assert_eq!(0x5421, buf.get_u16_le());
-    }
-
-    #[test]
-    #[should_panic]
-    fn test_get_u16_buffer_underflow() {
-        let mut buf = VecBuf::new(&[b"\x21"]);
-        buf.get_u16_be();
-    }
-
-    #[test]
-    fn test_bufs_vec() {
-        let buf = VecBuf::new(&[b"he", b"llo"]);
-
-        let b1: &[u8] = &mut [0];
-        let b2: &[u8] = &mut [0];
-
-        let mut dst: [&IoVec; 2] =
-            [b1.into(), b2.into()];
-
-        assert_eq!(2, buf.bytes_vec(&mut dst[..]));
-    }
-}
diff --git a/src/common/vecbuf.rs b/src/common/vecbuf.rs
new file mode 100644
index 0000000..dd40163
--- /dev/null
+++ b/src/common/vecbuf.rs
@@ -0,0 +1,122 @@
+use std::cmp::{ self, Ordering };
+use bytes::Buf;
+use iovec::IoVec;
+
+pub struct VecBuf<'a, 'b: 'a> {
+    pos: usize,
+    cur: usize,
+    inner: &'a [&'b [u8]]
+}
+
+impl<'a, 'b> VecBuf<'a, 'b> {
+    pub fn new(vbytes: &'a [&'b [u8]]) -> Self {
+        VecBuf { pos: 0, cur: 0, inner: vbytes }
+    }
+}
+
+impl<'a, 'b> Buf for VecBuf<'a, 'b> {
+    fn remaining(&self) -> usize {
+        let sum = self.inner
+            .iter()
+            .skip(self.pos)
+            .map(|bytes| bytes.len())
+            .sum::<usize>();
+        sum - self.cur
+    }
+
+    fn bytes(&self) -> &[u8] {
+        &self.inner[self.pos][self.cur..]
+    }
+
+    fn advance(&mut self, cnt: usize) {
+        let current = self.inner[self.pos].len();
+        match (self.cur + cnt).cmp(&current) {
+            Ordering::Equal => if self.pos + 1 < self.inner.len() {
+                self.pos += 1;
+                self.cur = 0;
+            } else {
+                self.cur += cnt;
+            },
+            Ordering::Greater => {
+                if self.pos + 1 < self.inner.len() {
+                    self.pos += 1;
+                }
+                let remaining = self.cur + cnt - current;
+                self.advance(remaining);
+            },
+            Ordering::Less => self.cur += cnt,
+        }
+    }
+
+    #[allow(needless_range_loop)]
+    fn bytes_vec<'c>(&'c self, dst: &mut [&'c IoVec]) -> usize {
+        let len = cmp::min(self.inner.len() - self.pos, dst.len());
+
+        if len > 0 {
+            dst[0] = self.bytes().into();
+        }
+
+        for i in 1..len {
+            dst[i] = self.inner[self.pos + i].into();
+        }
+
+        len
+    }
+}
+
+#[cfg(test)]
+mod test_vecbuf {
+    use super::*;
+
+    #[test]
+    fn test_fresh_cursor_vec() {
+        let mut buf = VecBuf::new(&[b"he", b"llo"]);
+
+        assert_eq!(buf.remaining(), 5);
+        assert_eq!(buf.bytes(), b"he");
+
+        buf.advance(2);
+
+        assert_eq!(buf.remaining(), 3);
+        assert_eq!(buf.bytes(), b"llo");
+
+        buf.advance(3);
+
+        assert_eq!(buf.remaining(), 0);
+        assert_eq!(buf.bytes(), b"");
+    }
+
+    #[test]
+    fn test_get_u8() {
+        let mut buf = VecBuf::new(&[b"\x21z", b"omg"]);
+        assert_eq!(0x21, buf.get_u8());
+    }
+
+    #[test]
+    fn test_get_u16() {
+        let mut buf = VecBuf::new(&[b"\x21\x54z", b"omg"]);
+        assert_eq!(0x2154, buf.get_u16_be());
+        let mut buf = VecBuf::new(&[b"\x21\x54z", b"omg"]);
+        assert_eq!(0x5421, buf.get_u16_le());
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_get_u16_buffer_underflow() {
+        let mut buf = VecBuf::new(&[b"\x21"]);
+        buf.get_u16_be();
+    }
+
+    #[test]
+    fn test_bufs_vec() {
+        let buf = VecBuf::new(&[b"he", b"llo"]);
+
+        let b1: &[u8] = &mut [0];
+        let b2: &[u8] = &mut [0];
+
+        let mut dst: [&IoVec; 2] =
+            [b1.into(), b2.into()];
+
+        assert_eq!(2, buf.bytes_vec(&mut dst[..]));
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 9d910e1..b06c227 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,12 +1,17 @@
 //! Asynchronous TLS/SSL streams for Tokio using [Rustls](https://github.com/ctz/rustls).
 
-#![feature(specialization)]
+#![cfg_attr(feature = "nightly", feature(specialization))]
 
 pub extern crate rustls;
 pub extern crate webpki;
 
+#[cfg(feature = "tokio-support")]
 extern crate tokio;
+#[cfg(feature = "nightly")]
+#[cfg(feature = "tokio-support")]
 extern crate bytes;
+#[cfg(feature = "nightly")]
+#[cfg(feature = "tokio-support")]
 extern crate iovec;