diff --git a/src/core/Akka.Tests/Actor/InboxSpec.cs b/src/core/Akka.Tests/Actor/InboxSpec.cs
index ca606fb022a..aadf1e6217e 100644
--- a/src/core/Akka.Tests/Actor/InboxSpec.cs
+++ b/src/core/Akka.Tests/Actor/InboxSpec.cs
@@ -13,6 +13,7 @@
 using Akka.Actor.Internal;
 using Akka.Event;
 using Akka.TestKit;
+using Akka.Tests.Util;
 using Xunit;
 
 namespace Akka.Tests.Actor
@@ -28,13 +29,13 @@ public InboxSpec()
         }
 
         [Fact]
-        public void Inbox_support_watch()
+        public async Task Inbox_support_watch()
         {
             _inbox.Watch(TestActor);
 
             // check watch
             TestActor.Tell(PoisonPill.Instance);
-            var received = _inbox.Receive(TimeSpan.FromSeconds(1));
+            var received = await _inbox.ReceiveAsync(TimeSpan.FromSeconds(1));
 
             received.GetType().ShouldBe(typeof(Terminated));
             var terminated = (Terminated)received;
@@ -82,7 +83,7 @@ public void Inbox_support_selective_receives()
         }
 
         [Fact]
-        public void Inbox_have_maximum_queue_size()
+        public async Task Inbox_have_maximum_queue_size()
         {
             try
             {
@@ -90,14 +91,14 @@ public void Inbox_have_maximum_queue_size()
                 foreach (var zero in Enumerable.Repeat(0, 1000))
                     _inbox.Receiver.Tell(zero);
 
-                ExpectNoMsg(TimeSpan.FromSeconds(1));
+                await ExpectNoMsgAsync(TimeSpan.FromSeconds(1));
 
                 //The inbox is full. Sending another message should result in a Warning message
-                EventFilter.Warning(start:"Dropping message").ExpectOne(() => _inbox.Receiver.Tell(42));
+                await EventFilter.Warning(start:"Dropping message").ExpectOneAsync(() => _inbox.Receiver.Tell(42));
 
                 //The inbox is still full. But since the warning message has already been sent, no more warnings should be sent
                 _inbox.Receiver.Tell(42);
-                ExpectNoMsg(TimeSpan.FromSeconds(1));
+                await ExpectNoMsgAsync(TimeSpan.FromSeconds(1));
 
                 //Receive all messages from the inbox
                 var gotit = Enumerable.Repeat(0, 1000).Select(_ => _inbox.Receive());
@@ -107,7 +108,7 @@ public void Inbox_have_maximum_queue_size()
                 }
 
                 //The inbox should be empty now, so receiving should result in a timeout
-                Intercept<TimeoutException>(() =>
+                Assert.Throws<TimeoutException>(() =>
                 {
                     var received = _inbox.Receive(TimeSpan.FromSeconds(1));
                     Log.Error("Received " + received);
@@ -120,18 +121,17 @@ public void Inbox_have_maximum_queue_size()
         }
 
         [Fact]
-        public void Inbox_have_a_default_and_custom_timeouts()
+        public async Task Inbox_have_a_default_and_custom_timeouts()
         {
-            Within(TimeSpan.FromSeconds(4), TimeSpan.FromSeconds(6), () =>
+            await WithinAsync(TimeSpan.FromSeconds(4), TimeSpan.FromSeconds(6), () =>
             {
-                Intercept<TimeoutException>(() => _inbox.Receive());
+                Assert.Throws<TimeoutException>(() => _inbox.Receive());
                 return true;
             });
 
-            Within(TimeSpan.FromSeconds(1), () =>
+            await WithinAsync(TimeSpan.FromSeconds(1), () =>
             {
-                Intercept<TimeoutException>(() => _inbox.Receive(TimeSpan.FromMilliseconds(100)));
-                return true;
+                Assert.Throws<TimeoutException>(() => _inbox.Receive(TimeSpan.FromMilliseconds(100)));
             });
         }
 
@@ -152,11 +152,10 @@ public void Select_WithClient_should_update_Client_and_copy_the_rest_of_the_prop
         }
 
         [Fact]
-        public void Inbox_Receive_will_timeout_gracefully_if_timeout_is_already_expired()
+        public async Task Inbox_Receive_will_timeout_gracefully_if_timeout_is_already_expired()
         {
             var task = _inbox.ReceiveAsync(TimeSpan.FromSeconds(-1));
-
-            Assert.True(task.Wait(1000), "Receive did not complete in time.");
+            Assert.True(await task.AwaitWithTimeout(TimeSpan.FromMilliseconds(1000)), "Receive did not complete in time.");
             Assert.IsType<Status.Failure>(task.Result);
         }
     }