diff --git a/actix-rt/Cargo.toml b/actix-rt/Cargo.toml
index 7990e67d..e7ce06be 100644
--- a/actix-rt/Cargo.toml
+++ b/actix-rt/Cargo.toml
@@ -26,6 +26,7 @@ macros = ["actix-macros"]
 actix-macros = { version = "0.2.0", optional = true }
 
 futures-core = { version = "0.3", default-features = false }
+futures-intrusive = "0.4"
 tokio = { version = "1.2", features = ["rt", "net", "parking_lot", "signal", "sync", "time"] }
 
 [dev-dependencies]
diff --git a/actix-rt/src/arbiter.rs b/actix-rt/src/arbiter.rs
index 9ff1419d..634fc0ed 100644
--- a/actix-rt/src/arbiter.rs
+++ b/actix-rt/src/arbiter.rs
@@ -9,6 +9,9 @@ use std::{
 };
 
 use futures_core::ready;
+use futures_intrusive::channel::shared::{
+    oneshot_broadcast_channel, OneshotBroadcastReceiver, OneshotBroadcastSender,
+};
 use tokio::{sync::mpsc, task::LocalSet};
 
 use crate::{
@@ -40,11 +43,26 @@ impl fmt::Debug for ArbiterCommand {
 #[derive(Debug, Clone)]
 pub struct ArbiterHandle {
     tx: mpsc::UnboundedSender<ArbiterCommand>,
+    /// Is `None` for system arbiter.
+    stopped_rx: Option<OneshotBroadcastReceiver<()>>,
 }
 
 impl ArbiterHandle {
-    pub(crate) fn new(tx: mpsc::UnboundedSender<ArbiterCommand>) -> Self {
-        Self { tx }
+    pub(crate) fn new(
+        tx: mpsc::UnboundedSender<ArbiterCommand>,
+        stopped_rx: OneshotBroadcastReceiver<()>,
+    ) -> Self {
+        Self {
+            tx,
+            stopped_rx: Some(stopped_rx),
+        }
+    }
+
+    pub(crate) fn for_system(tx: mpsc::UnboundedSender<ArbiterCommand>) -> Self {
+        Self {
+            tx,
+            stopped_rx: None,
+        }
     }
 
     /// Send a future to the [Arbiter]'s thread and spawn it.
@@ -81,6 +99,25 @@ impl ArbiterHandle {
     pub fn stop(&self) -> bool {
         self.tx.send(ArbiterCommand::Stop).is_ok()
     }
+
+    /// Will wait for [Arbiter] to complete all commands up until it's Stop command is processed.
+    ///
+    /// For [Arbiter]s that have already stopped, the future will resolve immediately.
+    ///
+    /// # Panics
+    /// Panics if called on the system Arbiter. In this situation the Arbiter's lifetime is
+    /// implicitly bound by the main thread's lifetime.
+    pub async fn join(self) {
+        match self.stopped_rx {
+            Some(rx) => {
+                rx.receive().await;
+            }
+            None => {
+                // TODO: decide if this is correct
+                panic!("cannot wait on the system Arbiter's completion")
+            }
+        }
+    }
 }
 
 /// An Arbiter represents a thread that provides an asynchronous execution environment for futures
@@ -89,8 +126,10 @@ impl ArbiterHandle {
 /// When an arbiter is created, it spawns a new [OS thread](thread), and hosts an event loop.
 #[derive(Debug)]
 pub struct Arbiter {
-    tx: mpsc::UnboundedSender<ArbiterCommand>,
-    thread_handle: thread::JoinHandle<()>,
+    id: usize,
+    stopped_tx: OneshotBroadcastSender<()>,
+    cmd_tx: mpsc::UnboundedSender<ArbiterCommand>,
+    thread_handle: Option<thread::JoinHandle<()>>,
 }
 
 impl Arbiter {
@@ -99,7 +138,7 @@ impl Arbiter {
     /// # Panics
     /// Panics if a [System] is not registered on the current thread.
     #[allow(clippy::new_without_default)]
-    pub fn new() -> Arbiter {
+    pub fn new() -> ArbiterHandle {
         Self::with_tokio_rt(|| {
             default_tokio_runtime().expect("Cannot create new Arbiter's Runtime.")
         })
@@ -109,74 +148,109 @@ impl Arbiter {
     ///
     /// [tokio-runtime]: tokio::runtime::Runtime
     #[doc(hidden)]
-    pub fn with_tokio_rt<F>(runtime_factory: F) -> Arbiter
+    pub fn with_tokio_rt<F>(runtime_factory: F) -> ArbiterHandle
     where
         F: Fn() -> tokio::runtime::Runtime + Send + 'static,
     {
+        eprintln!("get sys current");
+
         let sys = System::current();
+        eprintln!("get sys id");
         let system_id = sys.id();
+        eprintln!("calc arb id");
         let arb_id = COUNT.fetch_add(1, Ordering::Relaxed);
 
         let name = format!("actix-rt|system:{}|arbiter:{}", system_id, arb_id);
-        let (tx, rx) = mpsc::unbounded_channel();
+        let (cmd_tx, cmd_rx) = mpsc::unbounded_channel();
 
-        let (ready_tx, ready_rx) = std::sync::mpsc::channel::<()>();
+        // let ready_barrier = Arc::new(Barrier::new(2));
 
+        let (stopped_tx, stopped_rx) = oneshot_broadcast_channel::<()>();
+
+        eprintln!("make arb handle");
+        let hnd = ArbiterHandle::new(cmd_tx.clone(), stopped_rx);
+
+        eprintln!("make thread");
         let thread_handle = thread::Builder::new()
             .name(name.clone())
             .spawn({
-                let tx = tx.clone();
-                move || {
-                    let rt = Runtime::from(runtime_factory());
-                    let hnd = ArbiterHandle::new(tx);
+                let hnd = hnd.clone();
+                // let ready_barrier = Arc::clone(&ready_barrier);
 
+                move || {
+                    eprintln!("thread: make rt");
+                    let rt = Runtime::from(runtime_factory());
+
+                    eprintln!("thread: set sys");
                     System::set_current(sys);
 
+                    // // wait until register message is sent
+                    // eprintln!("thread: wait for arb registered");
+                    // ready_barrier.wait();
+
+                    eprintln!("thread: set arb handle");
                     HANDLE.with(|cell| *cell.borrow_mut() = Some(hnd.clone()));
 
-                    // register arbiter
-                    let _ = System::current()
-                        .tx()
-                        .send(SystemCommand::RegisterArbiter(arb_id, hnd));
-
-                    ready_tx.send(()).unwrap();
-
                     // run arbiter event processing loop
-                    rt.block_on(ArbiterRunner { rx });
+                    eprintln!("thread: block on arbiter loop");
+                    rt.block_on(ArbiterLoop { cmd_rx });
 
                     // deregister arbiter
-                    let _ = System::current()
+                    eprintln!("thread: send deregister arbiter message");
+                    System::current()
                         .tx()
-                        .send(SystemCommand::DeregisterArbiter(arb_id));
+                        .send(SystemCommand::DeregisterArbiter(arb_id))
+                        .unwrap();
                 }
             })
             .unwrap_or_else(|err| {
                 panic!("Cannot spawn Arbiter's thread: {:?}. {:?}", &name, err)
             });
 
-        ready_rx.recv().unwrap();
+        let arb = Arbiter {
+            id: arb_id,
+            cmd_tx,
+            stopped_tx,
+            thread_handle: Some(thread_handle),
+        };
 
-        Arbiter { tx, thread_handle }
+        // register arbiter
+        eprintln!("send register arbiter message");
+        System::current()
+            .tx()
+            .send(SystemCommand::RegisterArbiter(arb))
+            .unwrap();
+
+        // eprintln!("inform arbiter that it is registered");
+        // ready_barrier.wait();
+
+        eprintln!("arbiter::new done");
+        hnd
     }
 
     /// Sets up an Arbiter runner in a new System using the provided runtime local task set.
-    pub(crate) fn in_new_system(local: &LocalSet) -> ArbiterHandle {
-        let (tx, rx) = mpsc::unbounded_channel();
+    pub(crate) fn for_system(local: &LocalSet) -> ArbiterHandle {
+        let (cmd_tx, cmd_rx) = mpsc::unbounded_channel();
 
-        let hnd = ArbiterHandle::new(tx);
+        let hnd = ArbiterHandle::for_system(cmd_tx);
 
         HANDLE.with(|cell| *cell.borrow_mut() = Some(hnd.clone()));
 
-        local.spawn_local(ArbiterRunner { rx });
+        local.spawn_local(ArbiterLoop { cmd_rx });
 
         hnd
     }
 
-    /// Return a handle to the this Arbiter's message sender.
-    pub fn handle(&self) -> ArbiterHandle {
-        ArbiterHandle::new(self.tx.clone())
+    /// Return `Arbiter`'s numeric ID.
+    pub(crate) fn id(&self) -> usize {
+        self.id
     }
 
+    // /// Return a handle to the this Arbiter's message sender.
+    // pub fn handle(&self) -> ArbiterHandle {
+    //     ArbiterHandle::new(self.cmd_tx.clone())
+    // }
+
     /// Return a handle to the current thread's Arbiter's message sender.
     ///
     /// # Panics
@@ -191,57 +265,68 @@ impl Arbiter {
     /// Stop Arbiter from continuing it's event loop.
     ///
     /// Returns true if stop message was sent successfully and false if the Arbiter has been dropped.
-    pub fn stop(&self) -> bool {
-        self.tx.send(ArbiterCommand::Stop).is_ok()
+    pub(crate) fn stop(&self) -> bool {
+        self.cmd_tx.send(ArbiterCommand::Stop).is_ok()
     }
 
-    /// Send a future to the Arbiter's thread and spawn it.
-    ///
-    /// If you require a result, include a response channel in the future.
-    ///
-    /// Returns true if future was sent successfully and false if the Arbiter has died.
-    pub fn spawn<Fut>(&self, future: Fut) -> bool
-    where
-        Fut: Future<Output = ()> + Send + 'static,
-    {
-        self.tx
-            .send(ArbiterCommand::Execute(Box::pin(future)))
-            .is_ok()
-    }
+    // /// Send a future to the Arbiter's thread and spawn it.
+    // ///
+    // /// If you require a result, include a response channel in the future.
+    // ///
+    // /// Returns true if future was sent successfully and false if the Arbiter has died.
+    // pub fn spawn<Fut>(&self, future: Fut) -> bool
+    // where
+    //     Fut: Future<Output = ()> + Send + 'static,
+    // {
+    //     self.cmd_tx
+    //         .send(ArbiterCommand::Execute(Box::pin(future)))
+    //         .is_ok()
+    // }
 
-    /// Send a function to the Arbiter's thread and execute it.
-    ///
-    /// Any result from the function is discarded. If you require a result, include a response
-    /// channel in the function.
-    ///
-    /// Returns true if function was sent successfully and false if the Arbiter has died.
-    pub fn spawn_fn<F>(&self, f: F) -> bool
-    where
-        F: FnOnce() + Send + 'static,
-    {
-        self.spawn(async { f() })
-    }
+    // /// Send a function to the Arbiter's thread and execute it.
+    // ///
+    // /// Any result from the function is discarded. If you require a result, include a response
+    // /// channel in the function.
+    // ///
+    // /// Returns true if function was sent successfully and false if the Arbiter has died.
+    // pub fn spawn_fn<F>(&self, f: F) -> bool
+    // where
+    //     F: FnOnce() + Send + 'static,
+    // {
+    //     self.spawn(async { f() })
+    // }
+}
 
-    /// Wait for Arbiter's event loop to complete.
-    ///
-    /// Joins the underlying OS thread handle. See [`JoinHandle::join`](thread::JoinHandle::join).
-    pub fn join(self) -> thread::Result<()> {
-        self.thread_handle.join()
+impl Drop for Arbiter {
+    fn drop(&mut self) {
+        eprintln!("Arb::drop: joining arbiter thread");
+        match self.thread_handle.take().unwrap().join() {
+            Ok(()) => {}
+            Err(err) => {
+                eprintln!("arbiter {} thread panicked: {:?}", self.id(), err)
+            }
+        }
+        eprintln!("Arb::drop: sending stopped tx");
+
+        // could fail if all handles are dropped already so ignore result
+        let _ = self.stopped_tx.send(());
+
+        eprintln!("Arb::drop: done");
     }
 }
 
 /// A persistent future that processes [Arbiter] commands.
-struct ArbiterRunner {
-    rx: mpsc::UnboundedReceiver<ArbiterCommand>,
+struct ArbiterLoop {
+    cmd_rx: mpsc::UnboundedReceiver<ArbiterCommand>,
 }
 
-impl Future for ArbiterRunner {
+impl Future for ArbiterLoop {
     type Output = ();
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         // process all items currently buffered in channel
         loop {
-            match ready!(Pin::new(&mut self.rx).poll_recv(cx)) {
+            match ready!(Pin::new(&mut self.cmd_rx).poll_recv(cx)) {
                 // channel closed; no more messages can be received
                 None => return Poll::Ready(()),
 
diff --git a/actix-rt/src/lib.rs b/actix-rt/src/lib.rs
index a529bdb0..0bce2114 100644
--- a/actix-rt/src/lib.rs
+++ b/actix-rt/src/lib.rs
@@ -16,12 +16,12 @@
 //!
 //! # Examples
 //! ```
-//! use std::sync::mpsc;
+//! use std::sync::mpsc::channel as std_channel;
 //! use actix_rt::{Arbiter, System};
 //!
-//! let _ = System::new();
+//! let sys = System::new();
 //!
-//! let (tx, rx) = mpsc::channel::<u32>();
+//! let (tx, rx) = std_channel::<u32>();
 //!
 //! let arbiter = Arbiter::new();
 //! arbiter.spawn_fn(move || tx.send(42).unwrap());
@@ -30,7 +30,10 @@
 //! assert_eq!(num, 42);
 //!
 //! arbiter.stop();
-//! arbiter.join().unwrap();
+//! sys.block_on(arbiter.join());
+//!
+//! System::current().stop();
+//! sys.run().unwrap();
 //! ```
 
 #![deny(rust_2018_idioms, nonstandard_style)]
diff --git a/actix-rt/src/system.rs b/actix-rt/src/system.rs
index 3bc8a6e3..81a75b12 100644
--- a/actix-rt/src/system.rs
+++ b/actix-rt/src/system.rs
@@ -54,14 +54,9 @@ impl System {
         let (sys_tx, sys_rx) = mpsc::unbounded_channel();
 
         let rt = Runtime::from(runtime_factory());
-        let sys_arbiter = Arbiter::in_new_system(rt.local_set());
+        let sys_arbiter = Arbiter::for_system(rt.local_set());
         let system = System::construct(sys_tx, sys_arbiter.clone());
 
-        system
-            .tx()
-            .send(SystemCommand::RegisterArbiter(usize::MAX, sys_arbiter))
-            .unwrap();
-
         // init background system arbiter
         let sys_ctrl = SystemController::new(sys_rx, stop_tx);
         rt.spawn(sys_ctrl);
@@ -150,7 +145,10 @@ impl System {
 }
 
 /// Runner that keeps a [System]'s event loop alive until stop message is received.
-#[must_use = "A SystemRunner does nothing unless `run` is called."]
+///
+/// Dropping the `SystemRunner` (eg. `let _ = System::new();`) will result in no further events
+/// being processed. It is required you bind the runner and call `run` or call `block_on`.
+#[must_use = "A SystemRunner does nothing unless `run` or `block_on` is called."]
 #[derive(Debug)]
 pub struct SystemRunner {
     rt: Runtime,
@@ -190,7 +188,7 @@ impl SystemRunner {
 #[derive(Debug)]
 pub(crate) enum SystemCommand {
     Exit(i32),
-    RegisterArbiter(usize, ArbiterHandle),
+    RegisterArbiter(Arbiter),
     DeregisterArbiter(usize),
 }
 
@@ -200,7 +198,7 @@ pub(crate) enum SystemCommand {
 pub(crate) struct SystemController {
     stop_tx: Option<oneshot::Sender<i32>>,
     cmd_rx: mpsc::UnboundedReceiver<SystemCommand>,
-    arbiters: HashMap<usize, ArbiterHandle>,
+    arbiters: HashMap<usize, Arbiter>,
 }
 
 impl SystemController {
@@ -221,35 +219,42 @@ impl Future for SystemController {
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
         // process all items currently buffered in channel
-        loop {
+        let code = loop {
             match ready!(Pin::new(&mut self.cmd_rx).poll_recv(cx)) {
                 // channel closed; no more messages can be received
-                None => return Poll::Ready(()),
+                None => break 0,
 
                 // process system command
                 Some(cmd) => match cmd {
                     SystemCommand::Exit(code) => {
                         // stop all arbiters
                         for arb in self.arbiters.values() {
+                            eprintln!("SystemController: stopping arbiter {}", arb.id());
                             arb.stop();
                         }
 
-                        // stop event loop
-                        // will only fire once
-                        if let Some(stop_tx) = self.stop_tx.take() {
-                            let _ = stop_tx.send(code);
-                        }
+                        eprintln!("SystemController: dropping arbiters");
+                        // destroy all arbiters
+                        // drop waits for threads to complete
+                        self.arbiters.clear();
+
+                        break code;
                     }
 
-                    SystemCommand::RegisterArbiter(id, arb) => {
-                        self.arbiters.insert(id, arb);
+                    SystemCommand::RegisterArbiter(arb) => {
+                        self.arbiters.insert(arb.id(), arb);
                     }
 
                     SystemCommand::DeregisterArbiter(id) => {
-                        self.arbiters.remove(&id);
+                        // implicit arbiter drop
+                        let _ = self.arbiters.remove(&id);
                     }
                 },
             }
-        }
+        };
+
+        self.stop_tx.take().unwrap().send(code).unwrap();
+
+        Poll::Ready(())
     }
 }
diff --git a/actix-rt/tests/multi_arbiter_check.rs b/actix-rt/tests/multi_arbiter_check.rs
new file mode 100644
index 00000000..ff2c66e3
--- /dev/null
+++ b/actix-rt/tests/multi_arbiter_check.rs
@@ -0,0 +1,44 @@
+//! Derived from this comment:
+//! https://github.com/actix/actix/issues/464#issuecomment-779427825
+
+use std::{thread, time::Duration};
+
+use actix_rt::{Arbiter, System};
+use tokio::sync::mpsc;
+
+#[test]
+fn actix_sample() {
+    let sys = System::new();
+    let arb = Arbiter::new();
+
+    let (_tx, mut rx) = mpsc::unbounded_channel::<()>();
+
+    // create "actor"
+    arb.spawn_fn(move || {
+        let a = A;
+
+        actix_rt::spawn(async move {
+            while let Some(_) = rx.recv().await {
+                println!("{:?}", a);
+            }
+        });
+    });
+
+    System::current().stop();
+
+    // all arbiters must be dropped when sys.run returns
+    sys.run().unwrap();
+
+    thread::sleep(Duration::from_millis(100));
+}
+
+#[derive(Debug)]
+struct A;
+
+impl Drop for A {
+    fn drop(&mut self) {
+        println!("start drop");
+        thread::sleep(Duration::from_millis(200));
+        println!("finish drop");
+    }
+}
diff --git a/actix-rt/tests/test_arbiter.rs b/actix-rt/tests/test_arbiter.rs
new file mode 100644
index 00000000..778ef6eb
--- /dev/null
+++ b/actix-rt/tests/test_arbiter.rs
@@ -0,0 +1,123 @@
+use std::{
+    sync::mpsc::channel as std_channel,
+    time::{Duration, Instant},
+};
+
+use actix_rt::{time, Arbiter, System};
+
+
+
+#[test]
+#[should_panic]
+fn no_system_arbiter_new_panic() {
+    Arbiter::new();
+}
+
+
+#[test]
+fn join_arbiter_wait_fut() {
+    let time = Duration::from_secs(1);
+    let instant = Instant::now();
+
+    System::new().block_on(async move {
+        let arbiter = Arbiter::new();
+
+        arbiter.spawn(async move {
+            time::sleep(time).await;
+            Arbiter::current().stop();
+        });
+
+        arbiter.join().await;
+    });
+
+    assert!(
+        instant.elapsed() >= time,
+        "Join on another arbiter should complete only when it calls stop"
+    );
+}
+
+#[test]
+fn join_arbiter_wait_fn() {
+    let time = Duration::from_secs(1);
+    let instant = Instant::now();
+
+    System::new().block_on(async move {
+        let arbiter = Arbiter::new();
+
+        arbiter.spawn_fn(move || {
+            actix_rt::spawn(async move {
+                time::sleep(time).await;
+                Arbiter::current().stop();
+            });
+        });
+
+        arbiter.join().await;
+    });
+
+    assert!(
+        instant.elapsed() >= time,
+        "Join on an arbiter that has used actix_rt::spawn should wait for said future"
+    );
+}
+
+#[test]
+fn join_arbiter_early_stop_call() {
+    let time = Duration::from_secs(1);
+    let instant = Instant::now();
+
+    System::new().block_on(async move {
+        let arbiter = Arbiter::new();
+
+        arbiter.spawn(Box::pin(async move {
+            time::sleep(time).await;
+            Arbiter::current().stop();
+        }));
+
+        arbiter.stop();
+        arbiter.join().await;
+    });
+
+    assert!(
+        instant.elapsed() < time,
+        "Premature stop of Arbiter should conclude regardless of it's current state."
+    );
+}
+
+#[test]
+fn arbiter_spawn_fn_runs() {
+    let sys = System::new();
+
+    let (tx, rx) = std_channel::<u32>();
+
+    let arbiter = Arbiter::new();
+    arbiter.spawn_fn(move || {
+        tx.send(42).unwrap();
+        System::current().stop();
+    });
+
+    let num = rx.recv().unwrap();
+    assert_eq!(num, 42);
+
+    sys.run().unwrap();
+}
+
+#[test]
+fn arbiter_inner_panic() {
+    let sys = System::new();
+
+    let (tx, rx) = std_channel::<u32>();
+
+    let arbiter = Arbiter::new();
+
+    // spawned panics should not cause arbiter to crash
+    arbiter.spawn(async { panic!("inner panic; will be caught") });
+    arbiter.spawn_fn(|| panic!("inner panic; will be caught"));
+
+    arbiter.spawn(async move { tx.send(42).unwrap() });
+
+    let num = rx.recv().unwrap();
+    assert_eq!(num, 42);
+
+    System::current().stop();
+    sys.run().unwrap();
+}
diff --git a/actix-rt/tests/test_runtime.rs b/actix-rt/tests/test_runtime.rs
new file mode 100644
index 00000000..f51196d2
--- /dev/null
+++ b/actix-rt/tests/test_runtime.rs
@@ -0,0 +1,82 @@
+use std::{
+    sync::{
+        atomic::{AtomicBool, Ordering},
+        mpsc::channel as std_channel,
+        Arc,
+    },
+    time::Duration,
+};
+
+use actix_rt::{Arbiter, System};
+
+#[test]
+fn wait_for_spawns() {
+    let rt = actix_rt::Runtime::new().unwrap();
+
+    let handle = rt.spawn(async {
+        println!("running on the runtime");
+        // assertion panic is caught at task boundary
+        assert_eq!(1, 2);
+    });
+
+    assert!(rt.block_on(handle).is_err());
+}
+
+#[test]
+fn new_system_with_tokio() {
+    let (tx, rx) = std_channel();
+
+    let res = System::with_tokio_rt(move || {
+        tokio::runtime::Builder::new_multi_thread()
+            .enable_io()
+            .enable_time()
+            .thread_keep_alive(Duration::from_millis(1000))
+            .worker_threads(2)
+            .max_blocking_threads(2)
+            .on_thread_start(|| {})
+            .on_thread_stop(|| {})
+            .build()
+            .unwrap()
+    })
+    .block_on(async {
+        actix_rt::time::sleep(Duration::from_millis(1)).await;
+
+        tokio::task::spawn(async move {
+            tx.send(42).unwrap();
+        })
+        .await
+        .unwrap();
+
+        123usize
+    });
+
+    assert_eq!(res, 123);
+    assert_eq!(rx.recv().unwrap(), 42);
+}
+
+#[test]
+fn new_arbiter_with_tokio() {
+    let sys = System::new();
+
+    let arb = Arbiter::with_tokio_rt(|| {
+        tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .unwrap()
+    });
+
+    let counter = Arc::new(AtomicBool::new(true));
+
+    let counter1 = counter.clone();
+    let did_spawn = arb.spawn(async move {
+        actix_rt::time::sleep(Duration::from_millis(1)).await;
+        counter1.store(false, Ordering::SeqCst);
+        Arbiter::current().stop();
+        System::current().stop();
+    });
+
+    sys.run().unwrap();
+
+    assert!(did_spawn);
+    assert_eq!(false, counter.load(Ordering::SeqCst));
+}
diff --git a/actix-rt/tests/test_system.rs b/actix-rt/tests/test_system.rs
new file mode 100644
index 00000000..a3900741
--- /dev/null
+++ b/actix-rt/tests/test_system.rs
@@ -0,0 +1,130 @@
+use std::{
+    sync::{
+        atomic::{AtomicBool, Ordering},
+        Arc,
+    },
+    thread,
+    time::{Duration, Instant},
+};
+
+use actix_rt::{time, Arbiter, System};
+use tokio::sync::oneshot;
+
+#[test]
+#[should_panic]
+fn no_system_current_panic() {
+    System::current();
+}
+
+#[test]
+fn try_current_no_system() {
+    assert!(System::try_current().is_none())
+}
+
+#[test]
+fn try_current_with_system() {
+    System::new().block_on(async { assert!(System::try_current().is_some()) });
+}
+
+#[test]
+fn non_static_block_on() {
+    let string = String::from("test_str");
+    let string = string.as_str();
+
+    let sys = System::new();
+
+    sys.block_on(async {
+        actix_rt::time::sleep(Duration::from_millis(1)).await;
+        assert_eq!("test_str", string);
+    });
+
+    let rt = actix_rt::Runtime::new().unwrap();
+
+    rt.block_on(async {
+        actix_rt::time::sleep(Duration::from_millis(1)).await;
+        assert_eq!("test_str", string);
+    });
+
+    System::current().stop();
+    sys.run().unwrap();
+}
+
+#[test]
+fn await_for_timer() {
+    let time = Duration::from_secs(1);
+    let instant = Instant::now();
+
+    System::new().block_on(async move {
+        time::sleep(time).await;
+    });
+
+    assert!(
+        instant.elapsed() >= time,
+        "Calling `block_on` should poll awaited future to completion."
+    );
+}
+
+#[test]
+fn system_arbiter_spawn() {
+    let runner = System::new();
+
+    let (tx, rx) = oneshot::channel();
+    let sys = System::current();
+
+    thread::spawn(|| {
+        // this thread will have no arbiter in it's thread local so call will panic
+        Arbiter::current();
+    })
+    .join()
+    .unwrap_err();
+
+    let thread = thread::spawn(|| {
+        // this thread will have no arbiter in it's thread local so use the system handle instead
+        System::set_current(sys);
+        let sys = System::current();
+
+        let arb = sys.arbiter();
+        arb.spawn(async move {
+            tx.send(42u32).unwrap();
+            System::current().stop();
+        });
+    });
+
+    assert_eq!(runner.block_on(rx).unwrap(), 42);
+    thread.join().unwrap();
+}
+
+struct Atom(Arc<AtomicBool>);
+
+impl Drop for Atom {
+    fn drop(&mut self) {
+        self.0.store(true, Ordering::SeqCst);
+    }
+}
+
+#[test]
+fn system_stop_arbiter_join_barrier() {
+    let sys = System::new();
+    let arb = Arbiter::new();
+
+    let atom = Atom(Arc::new(AtomicBool::new(false)));
+
+    // arbiter should be alive to receive spawn msg
+    assert!(Arbiter::current().spawn_fn(|| {}));
+    assert!(arb.spawn_fn(move || {
+        // thread should get dropped during sleep
+        thread::sleep(Duration::from_secs(2));
+
+        // pointless load to move atom into scope
+        atom.0.load(Ordering::SeqCst);
+
+        panic!("spawned fn (thread) should be dropped during sleep");
+    }));
+
+    System::current().stop();
+    sys.run().unwrap();
+
+    // arbiter should be dead and return false
+    assert!(!Arbiter::current().spawn_fn(|| {}));
+    assert!(!arb.spawn_fn(|| {}));
+}
diff --git a/actix-rt/tests/tests.rs b/actix-rt/tests/tests.rs
deleted file mode 100644
index 86fba96d..00000000
--- a/actix-rt/tests/tests.rs
+++ /dev/null
@@ -1,300 +0,0 @@
-use std::{
-    sync::{
-        atomic::{AtomicBool, Ordering},
-        mpsc::channel,
-        Arc,
-    },
-    thread,
-    time::{Duration, Instant},
-};
-
-use actix_rt::{Arbiter, System};
-use tokio::sync::oneshot;
-
-#[test]
-fn await_for_timer() {
-    let time = Duration::from_secs(1);
-    let instant = Instant::now();
-    System::new().block_on(async move {
-        tokio::time::sleep(time).await;
-    });
-    assert!(
-        instant.elapsed() >= time,
-        "Block on should poll awaited future to completion"
-    );
-}
-
-#[test]
-fn join_another_arbiter() {
-    let time = Duration::from_secs(1);
-    let instant = Instant::now();
-    System::new().block_on(async move {
-        let arbiter = Arbiter::new();
-        arbiter.spawn(Box::pin(async move {
-            tokio::time::sleep(time).await;
-            Arbiter::current().stop();
-        }));
-        arbiter.join().unwrap();
-    });
-    assert!(
-        instant.elapsed() >= time,
-        "Join on another arbiter should complete only when it calls stop"
-    );
-
-    let instant = Instant::now();
-    System::new().block_on(async move {
-        let arbiter = Arbiter::new();
-        arbiter.spawn_fn(move || {
-            actix_rt::spawn(async move {
-                tokio::time::sleep(time).await;
-                Arbiter::current().stop();
-            });
-        });
-        arbiter.join().unwrap();
-    });
-    assert!(
-        instant.elapsed() >= time,
-        "Join on an arbiter that has used actix_rt::spawn should wait for said future"
-    );
-
-    let instant = Instant::now();
-    System::new().block_on(async move {
-        let arbiter = Arbiter::new();
-        arbiter.spawn(Box::pin(async move {
-            tokio::time::sleep(time).await;
-            Arbiter::current().stop();
-        }));
-        arbiter.stop();
-        arbiter.join().unwrap();
-    });
-    assert!(
-        instant.elapsed() < time,
-        "Premature stop of arbiter should conclude regardless of it's current state"
-    );
-}
-
-#[test]
-fn non_static_block_on() {
-    let string = String::from("test_str");
-    let string = string.as_str();
-
-    let sys = System::new();
-
-    sys.block_on(async {
-        actix_rt::time::sleep(Duration::from_millis(1)).await;
-        assert_eq!("test_str", string);
-    });
-
-    let rt = actix_rt::Runtime::new().unwrap();
-
-    rt.block_on(async {
-        actix_rt::time::sleep(Duration::from_millis(1)).await;
-        assert_eq!("test_str", string);
-    });
-}
-
-#[test]
-fn wait_for_spawns() {
-    let rt = actix_rt::Runtime::new().unwrap();
-
-    let handle = rt.spawn(async {
-        println!("running on the runtime");
-        // assertion panic is caught at task boundary
-        assert_eq!(1, 2);
-    });
-
-    assert!(rt.block_on(handle).is_err());
-}
-
-#[test]
-fn arbiter_spawn_fn_runs() {
-    let _ = System::new();
-
-    let (tx, rx) = channel::<u32>();
-
-    let arbiter = Arbiter::new();
-    arbiter.spawn_fn(move || tx.send(42).unwrap());
-
-    let num = rx.recv().unwrap();
-    assert_eq!(num, 42);
-
-    arbiter.stop();
-    arbiter.join().unwrap();
-}
-
-#[test]
-fn arbiter_handle_spawn_fn_runs() {
-    let sys = System::new();
-
-    let (tx, rx) = channel::<u32>();
-
-    let arbiter = Arbiter::new();
-    let handle = arbiter.handle();
-    drop(arbiter);
-
-    handle.spawn_fn(move || {
-        tx.send(42).unwrap();
-        System::current().stop()
-    });
-
-    let num = rx.recv_timeout(Duration::from_secs(2)).unwrap();
-    assert_eq!(num, 42);
-
-    handle.stop();
-    sys.run().unwrap();
-}
-
-#[test]
-fn arbiter_drop_no_panic_fn() {
-    let _ = System::new();
-
-    let arbiter = Arbiter::new();
-    arbiter.spawn_fn(|| panic!("test"));
-
-    arbiter.stop();
-    arbiter.join().unwrap();
-}
-
-#[test]
-fn arbiter_drop_no_panic_fut() {
-    let _ = System::new();
-
-    let arbiter = Arbiter::new();
-    arbiter.spawn(async { panic!("test") });
-
-    arbiter.stop();
-    arbiter.join().unwrap();
-}
-
-#[test]
-#[should_panic]
-fn no_system_current_panic() {
-    System::current();
-}
-
-#[test]
-#[should_panic]
-fn no_system_arbiter_new_panic() {
-    Arbiter::new();
-}
-
-#[test]
-fn system_arbiter_spawn() {
-    let runner = System::new();
-
-    let (tx, rx) = oneshot::channel();
-    let sys = System::current();
-
-    thread::spawn(|| {
-        // this thread will have no arbiter in it's thread local so call will panic
-        Arbiter::current();
-    })
-    .join()
-    .unwrap_err();
-
-    let thread = thread::spawn(|| {
-        // this thread will have no arbiter in it's thread local so use the system handle instead
-        System::set_current(sys);
-        let sys = System::current();
-
-        let arb = sys.arbiter();
-        arb.spawn(async move {
-            tx.send(42u32).unwrap();
-            System::current().stop();
-        });
-    });
-
-    assert_eq!(runner.block_on(rx).unwrap(), 42);
-    thread.join().unwrap();
-}
-
-#[test]
-fn system_stop_stops_arbiters() {
-    let sys = System::new();
-    let arb = Arbiter::new();
-
-    // arbiter should be alive to receive spawn msg
-    assert!(Arbiter::current().spawn_fn(|| {}));
-    assert!(arb.spawn_fn(|| {}));
-
-    System::current().stop();
-    sys.run().unwrap();
-
-    // account for slightly slow thread de-spawns (only observed on windows)
-    thread::sleep(Duration::from_millis(100));
-
-    // arbiter should be dead and return false
-    assert!(!Arbiter::current().spawn_fn(|| {}));
-    assert!(!arb.spawn_fn(|| {}));
-
-    arb.join().unwrap();
-}
-
-#[test]
-fn new_system_with_tokio() {
-    let (tx, rx) = channel();
-
-    let res = System::with_tokio_rt(move || {
-        tokio::runtime::Builder::new_multi_thread()
-            .enable_io()
-            .enable_time()
-            .thread_keep_alive(Duration::from_millis(1000))
-            .worker_threads(2)
-            .max_blocking_threads(2)
-            .on_thread_start(|| {})
-            .on_thread_stop(|| {})
-            .build()
-            .unwrap()
-    })
-    .block_on(async {
-        actix_rt::time::sleep(Duration::from_millis(1)).await;
-
-        tokio::task::spawn(async move {
-            tx.send(42).unwrap();
-        })
-        .await
-        .unwrap();
-
-        123usize
-    });
-
-    assert_eq!(res, 123);
-    assert_eq!(rx.recv().unwrap(), 42);
-}
-
-#[test]
-fn new_arbiter_with_tokio() {
-    let _ = System::new();
-
-    let arb = Arbiter::with_tokio_rt(|| {
-        tokio::runtime::Builder::new_current_thread()
-            .enable_all()
-            .build()
-            .unwrap()
-    });
-
-    let counter = Arc::new(AtomicBool::new(true));
-
-    let counter1 = counter.clone();
-    let did_spawn = arb.spawn(async move {
-        actix_rt::time::sleep(Duration::from_millis(1)).await;
-        counter1.store(false, Ordering::SeqCst);
-        Arbiter::current().stop();
-    });
-
-    assert!(did_spawn);
-
-    arb.join().unwrap();
-
-    assert_eq!(false, counter.load(Ordering::SeqCst));
-}
-
-#[test]
-fn try_current_no_system() {
-    assert!(System::try_current().is_none())
-}
-
-#[test]
-fn try_current_with_system() {
-    System::new().block_on(async { assert!(System::try_current().is_some()) });
-}
diff --git a/rustfmt.toml b/rustfmt.toml
index 2e19d167..973e002c 100644
--- a/rustfmt.toml
+++ b/rustfmt.toml
@@ -1,5 +1,2 @@
 max_width = 96
 reorder_imports = true
-#wrap_comments = true
-#fn_args_density = "Compressed"
-#use_small_heuristics = false