diff --git a/src/client/pipeline.rs b/src/client/pipeline.rs
index c2caf83c..de1ff128 100644
--- a/src/client/pipeline.rs
+++ b/src/client/pipeline.rs
@@ -317,9 +317,6 @@ impl Pipeline {
         if self.conn.is_none() {
             return Ok(Async::Ready(None));
         }
-        let conn: &mut Connection =
-            unsafe { &mut *(self.conn.as_mut().unwrap() as *mut _) };
-
         let mut need_run = false;
 
         // need write?
@@ -337,6 +334,9 @@ impl Pipeline {
 
         // need read?
         if self.parser.is_some() {
+            let conn: &mut Connection =
+                unsafe { &mut *(self.conn.as_mut().unwrap() as *mut _) };
+
             loop {
                 match self
                     .parser
diff --git a/src/extensions.rs b/src/extensions.rs
index 1c64623f..7fdd142b 100644
--- a/src/extensions.rs
+++ b/src/extensions.rs
@@ -48,7 +48,6 @@ impl Extensions {
     /// If a extension of this type existed, it will be returned.
     pub fn remove<T: 'static>(&mut self) -> Option<T> {
         self.map.remove(&TypeId::of::<T>()).and_then(|boxed| {
-            //TODO: we can use unsafe and remove double checking the type id
             (boxed as Box<Any + 'static>)
                 .downcast()
                 .ok()
diff --git a/src/ws/client.rs b/src/ws/client.rs
index 7cf0095d..5087c885 100644
--- a/src/ws/client.rs
+++ b/src/ws/client.rs
@@ -1,5 +1,5 @@
 //! Http client request
-use std::cell::UnsafeCell;
+use std::cell::RefCell;
 use std::rc::Rc;
 use std::time::Duration;
 use std::{fmt, io, str};
@@ -422,7 +422,7 @@ impl Future for ClientHandshake {
             closed: false,
         };
 
-        let inner = Rc::new(UnsafeCell::new(inner));
+        let inner = Rc::new(RefCell::new(inner));
         Ok(Async::Ready((
             ClientReader {
                 inner: Rc::clone(&inner),
@@ -435,7 +435,7 @@ impl Future for ClientHandshake {
 
 /// Websocket reader client
 pub struct ClientReader {
-    inner: Rc<UnsafeCell<Inner>>,
+    inner: Rc<RefCell<Inner>>,
     max_size: usize,
 }
 
@@ -451,7 +451,7 @@ impl Stream for ClientReader {
 
     fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
         let max_size = self.max_size;
-        let inner: &mut Inner = unsafe { &mut *self.inner.get() };
+        let mut inner = self.inner.borrow_mut();
         if inner.closed {
             return Ok(Async::Ready(None));
         }
@@ -507,14 +507,14 @@ impl Stream for ClientReader {
 
 /// Websocket writer client
 pub struct ClientWriter {
-    inner: Rc<UnsafeCell<Inner>>,
+    inner: Rc<RefCell<Inner>>,
 }
 
 impl ClientWriter {
     /// Write payload
     #[inline]
     fn write(&mut self, mut data: Binary) {
-        let inner: &mut Inner = unsafe { &mut *self.inner.get() };
+        let inner = self.inner.borrow_mut();
         if !inner.closed {
             let _ = inner.tx.unbounded_send(data.take());
         } else {