diff --git a/core/tests/transport_upgrade.rs b/core/tests/transport_upgrade.rs
index ecba64dfb2f..723a04b0780 100644
--- a/core/tests/transport_upgrade.rs
+++ b/core/tests/transport_upgrade.rs
@@ -18,8 +18,6 @@
 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-mod util;
-
 use futures::prelude::*;
 use libp2p_core::identity;
 use libp2p_core::transport::{MemoryTransport, Transport};
@@ -91,11 +89,6 @@ fn upgrade_pipeline() {
         .apply(HelloUpgrade {})
         .apply(HelloUpgrade {})
         .multiplex(MplexConfig::default())
-        .and_then(|(peer, mplex), _| {
-            // Gracefully close the connection to allow protocol
-            // negotiation to complete.
-            util::CloseMuxer::new(mplex).map_ok(move |mplex| (peer, mplex))
-        })
         .boxed();
 
     let dialer_keys = identity::Keypair::generate_ed25519();
@@ -110,11 +103,6 @@ fn upgrade_pipeline() {
         .apply(HelloUpgrade {})
         .apply(HelloUpgrade {})
         .multiplex(MplexConfig::default())
-        .and_then(|(peer, mplex), _| {
-            // Gracefully close the connection to allow protocol
-            // negotiation to complete.
-            util::CloseMuxer::new(mplex).map_ok(move |mplex| (peer, mplex))
-        })
         .boxed();
 
     let listen_addr1 = Multiaddr::from(Protocol::Memory(random::<u64>()));
diff --git a/core/tests/util.rs b/core/tests/util.rs
deleted file mode 100644
index 7ca52188a52..00000000000
--- a/core/tests/util.rs
+++ /dev/null
@@ -1,47 +0,0 @@
-#![allow(dead_code)]
-
-use futures::prelude::*;
-use libp2p_core::muxing::StreamMuxer;
-use std::{pin::Pin, task::Context, task::Poll};
-
-pub struct CloseMuxer<M> {
-    state: CloseMuxerState<M>,
-}
-
-impl<M> CloseMuxer<M> {
-    pub fn new(m: M) -> CloseMuxer<M> {
-        CloseMuxer {
-            state: CloseMuxerState::Close(m),
-        }
-    }
-}
-
-pub enum CloseMuxerState<M> {
-    Close(M),
-    Done,
-}
-
-impl<M> Future for CloseMuxer<M>
-where
-    M: StreamMuxer,
-    M::Error: From<std::io::Error>,
-{
-    type Output = Result<M, M::Error>;
-
-    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        loop {
-            match std::mem::replace(&mut self.state, CloseMuxerState::Done) {
-                CloseMuxerState::Close(muxer) => {
-                    if !muxer.poll_close(cx)?.is_ready() {
-                        self.state = CloseMuxerState::Close(muxer);
-                        return Poll::Pending;
-                    }
-                    return Poll::Ready(Ok(muxer));
-                }
-                CloseMuxerState::Done => panic!(),
-            }
-        }
-    }
-}
-
-impl<M> Unpin for CloseMuxer<M> {}