diff -Naur a/tests/support/mod.rs b/tests/support/mod.rs
--- a/tests/support/mod.rs	1969-12-31 16:00:00.000000000 -0800
+++ b/tests/support/mod.rs	2021-07-14 21:47:18.502065660 -0700
@@ -61,42 +61,6 @@
     }
 }
 
-impl<R> tokio_03_dep::io::AsyncRead for PartialAsyncRead<R>
-where
-    R: tokio_03_dep::io::AsyncRead + Unpin,
-{
-    fn poll_read(
-        mut self: Pin<&mut Self>,
-        cx: &mut task::Context<'_>,
-        buf: &mut tokio_03_dep::io::ReadBuf<'_>,
-    ) -> Poll<io::Result<()>> {
-        match self.ops.next() {
-            Some(PartialOp::Limited(n)) => {
-                let len = std::cmp::min(n, buf.remaining());
-                buf.initialize_unfilled();
-                let mut sub_buf = buf.take(len);
-                ready!(Pin::new(&mut self.inner).poll_read(cx, &mut sub_buf))?;
-                let filled = sub_buf.filled().len();
-                buf.advance(filled);
-                Poll::Ready(Ok(()))
-            }
-            Some(PartialOp::Err(err)) => {
-                if err == io::ErrorKind::WouldBlock {
-                    cx.waker().wake_by_ref();
-                    Poll::Pending
-                } else {
-                    Err(io::Error::new(
-                        err,
-                        "error during read, generated by partial-io",
-                    ))
-                    .into()
-                }
-            }
-            Some(PartialOp::Unlimited) | None => Pin::new(&mut self.inner).poll_read(cx, buf),
-        }
-    }
-}
-
 impl<R> tokio_dep::io::AsyncRead for PartialAsyncRead<R>
 where
     R: tokio_dep::io::AsyncRead + Unpin,