diff --git a/imports/wasi_snapshot_preview1/testdata/cargo-wasi/Cargo.toml b/imports/wasi_snapshot_preview1/testdata/cargo-wasi/Cargo.toml
index f1e93d7b4e5..8282d207977 100644
--- a/imports/wasi_snapshot_preview1/testdata/cargo-wasi/Cargo.toml
+++ b/imports/wasi_snapshot_preview1/testdata/cargo-wasi/Cargo.toml
@@ -9,3 +9,4 @@ path = "wasi.rs"
 
 [dependencies]
 libc = "0.2"
+mio = {version="0.8", features=["os-poll", "net"]}
diff --git a/imports/wasi_snapshot_preview1/testdata/cargo-wasi/wasi.rs b/imports/wasi_snapshot_preview1/testdata/cargo-wasi/wasi.rs
index 3641e539492..d0345483cad 100644
--- a/imports/wasi_snapshot_preview1/testdata/cargo-wasi/wasi.rs
+++ b/imports/wasi_snapshot_preview1/testdata/cargo-wasi/wasi.rs
@@ -6,6 +6,10 @@ use std::net::{TcpListener};
 use std::os::wasi::io::FromRawFd;
 use std::process::exit;
 use std::str::from_utf8;
+use std::error::Error;
+
+use std::collections::HashMap;
+use std::time::Duration;
 
 // Until NotADirectory is implemented, read the underlying error raised by
 // wasi-libc. See https://github.com/rust-lang/rust/issues/86442
@@ -23,6 +27,7 @@ fn main() {
         }
         "stat" => main_stat(),
         "sock" => main_sock(),
+        "mixed" => main_mixed().unwrap(),
         _ => {
             writeln!(io::stderr(), "unknown command: {}", args[1]).unwrap();
             exit(1);
@@ -87,3 +92,103 @@ fn main_sock() {
         }
     }
 }
+
+fn main_mixed() -> Result<(), Box<dyn Error>> {
+
+    use mio::net::{TcpListener, TcpStream};
+    use mio::{Events, Interest, Poll, Token};
+
+    // Some tokens to allow us to identify which event is for which socket.
+    const SERVER: Token = Token(0);
+    const STDIN: Token = Token(1);
+
+    // Create a poll instance.
+    let mut poll = Poll::new()?;
+    // Create storage for events.
+    let mut events = Events::with_capacity(128);
+
+    let mut server = unsafe { TcpListener::from_raw_fd(3) };
+    let mut stdin = unsafe { TcpStream::from_raw_fd(0) };
+
+
+    // Start listening for incoming connections.
+    poll.registry()
+        .register(&mut server, SERVER, Interest::READABLE)?;
+
+    // Keep track of incoming connections.
+    let mut m: HashMap<Token, TcpStream> = HashMap::new();
+
+    let mut count = 2;
+
+    // Start an event loop.
+    loop {
+        // Poll Mio for events, blocking until we get an event.
+        if let Err(e) = poll.poll(&mut events, Some(Duration::from_nanos(0))) {
+            // Ignore EINTR.
+            if e.kind() == std::io::ErrorKind::Interrupted {
+                continue;
+            }
+            return Err(Box::from(e))
+        }
+
+        // Process each event.
+        for event in events.iter() {
+            // We can use the token we previously provided to `register` to
+            // determine for which socket the event is.
+            match event.token() {
+                    SERVER => {
+                    // If this is an event for the server, it means a connection
+                    // is ready to be accepted.
+                    //
+                    // Accept the connection and add it to the map.
+                    match server.accept() {
+                        Ok((mut connection, _addr)) => {
+                            let tok = Token(count);
+                            _ = poll.registry()
+                                .register(&mut connection, tok, Interest::READABLE);
+                            m.insert(tok, connection);
+                            // drop(connection);
+                            count+=1;
+                        },
+                        Err(e) if e.kind() == std::io::ErrorKind::WouldBlock => {
+                            // ignore
+                        },
+                        Err(err) => panic!("ERROR! {}", err),
+                    }
+                },
+
+                STDIN => {
+                    // There is for reading on one of our connections, read it and echo.
+                    let mut buf = [0u8; 32];
+                    match stdin.read(&mut buf) {
+                        Ok(n) if n>0 =>
+                            println!("{}", String::from_utf8_lossy(&buf[0..n])),
+                        _ => {} // ignore error.
+                    }
+                },
+
+
+                conn_id => {
+                    // There is for reading on one of our connections, read it and echo.
+                    let mut buf = [0u8; 32];
+                    let mut el = m.get(&conn_id).unwrap();
+                    match el.read(&mut buf) {
+                        Ok(n) if n>0 => {
+                            let s = String::from_utf8_lossy(&buf[0..n]);
+                            println!("{}", s);
+                            // Quit when the socket contains the string wazero.
+                            if s.contains("wazero") {
+                                return Ok(());
+                            }
+                        },
+
+                        _ => {} // ignore error.
+                    }
+                }
+            }
+        }
+
+    }
+}
+
+
diff --git a/imports/wasi_snapshot_preview1/testdata/cargo-wasi/wasi.wasm b/imports/wasi_snapshot_preview1/testdata/cargo-wasi/wasi.wasm
index 2ddde1064d2..8cafb21ed2e 100644
Binary files a/imports/wasi_snapshot_preview1/testdata/cargo-wasi/wasi.wasm and b/imports/wasi_snapshot_preview1/testdata/cargo-wasi/wasi.wasm differ
diff --git a/imports/wasi_snapshot_preview1/wasi_stdlib_test.go b/imports/wasi_snapshot_preview1/wasi_stdlib_test.go
index f29c2e1f4d0..9007ff24343 100644
--- a/imports/wasi_snapshot_preview1/wasi_stdlib_test.go
+++ b/imports/wasi_snapshot_preview1/wasi_stdlib_test.go
@@ -640,8 +640,8 @@ func testLargeStdout(t *testing.T, tname string, bin []byte) {
 
 func Test_Mixed(t *testing.T) {
 	toolchains := map[string][]byte{
-		// TODO: "cargo-wasi": wasmCargoWasi,
-		"zig-cc": wasmZigCc,
+		"cargo-wasi": wasmCargoWasi,
+		"zig-cc":     wasmZigCc,
 	}
 	if wasmGotip != nil {
 		toolchains["gotip"] = wasmGotip