diff --git a/Frameworks/MQTTnet.NetStandard/Internal/AsyncAutoResetEvent.cs b/Frameworks/MQTTnet.NetStandard/Internal/AsyncAutoResetEvent.cs
index 0a304e6..a8fa852 100644
--- a/Frameworks/MQTTnet.NetStandard/Internal/AsyncAutoResetEvent.cs
+++ b/Frameworks/MQTTnet.NetStandard/Internal/AsyncAutoResetEvent.cs
@@ -12,7 +12,10 @@ namespace MQTTnet.Internal
 
         private bool isSignaled;
 
-        public AsyncAutoResetEvent(bool signaled = false)
+        public AsyncAutoResetEvent() : this(false)
+        { }
+
+        public AsyncAutoResetEvent(bool signaled)
         {
             this.isSignaled = signaled;
         }
@@ -56,7 +59,7 @@ namespace MQTTnet.Internal
                 }
             }
 
-            Task winner = await Task.WhenAny(tcs.Task, Task.Delay(timeout, cancellationToken));
+            Task winner = await Task.WhenAny(tcs.Task, Task.Delay(timeout, cancellationToken)).ConfigureAwait(false);
             if (winner == tcs.Task)
             {
                 // The task was signaled.
@@ -68,7 +71,7 @@ namespace MQTTnet.Internal
                 // This is an O(n) operation since waiters is a LinkedList<T>.
                 lock (this.waiters)
                 {
-                    bool removed = this.waiters.Remove(tcs);
+                    this.waiters.Remove(tcs);
                     if (winner.Status == TaskStatus.Canceled)
                     {
                         throw new OperationCanceledException(cancellationToken);
diff --git a/Frameworks/MQTTnet.NetStandard/Internal/AsyncLock.cs b/Frameworks/MQTTnet.NetStandard/Internal/AsyncLock.cs
index d402949..5e60a6a 100644
--- a/Frameworks/MQTTnet.NetStandard/Internal/AsyncLock.cs
+++ b/Frameworks/MQTTnet.NetStandard/Internal/AsyncLock.cs
@@ -5,7 +5,7 @@ using System.Threading.Tasks;
 namespace MQTTnet.Internal
 {
     // From Stephen Toub (https://blogs.msdn.microsoft.com/pfxteam/2012/02/12/building-async-coordination-primitives-part-6-asynclock/)
-    public sealed class AsyncLock
+    public sealed class AsyncLock : IDisposable
     {
         private readonly SemaphoreSlim m_semaphore = new SemaphoreSlim(1, 1);
         private readonly Task<IDisposable> m_releaser;
@@ -25,6 +25,11 @@ namespace MQTTnet.Internal
                             TaskContinuationOptions.ExecuteSynchronously, TaskScheduler.Default);
         }
 
+        public void Dispose()
+        {
+            this.m_semaphore?.Dispose();
+        }
+
         private sealed class Releaser : IDisposable
         {
             private readonly AsyncLock m_toRelease;
diff --git a/Tests/MQTTnet.Core.Tests/AsyncAutoResentEventTests.cs b/Tests/MQTTnet.Core.Tests/AsyncAutoResentEventTests.cs
index 879f925..a4909b4 100644
--- a/Tests/MQTTnet.Core.Tests/AsyncAutoResentEventTests.cs
+++ b/Tests/MQTTnet.Core.Tests/AsyncAutoResentEventTests.cs
@@ -10,7 +10,7 @@ namespace MQTTnet.Core.Tests
     // Inspired from the vs-threading tests (https://github.com/Microsoft/vs-threading/blob/master/src/Microsoft.VisualStudio.Threading.Tests/AsyncAutoResetEventTests.cs)
     public class AsyncAutoResetEventTests
     {
-        private AsyncAutoResetEvent evt;
+        private readonly AsyncAutoResetEvent evt;
 
         public AsyncAutoResetEventTests()
         {
@@ -57,7 +57,7 @@ namespace MQTTnet.Core.Tests
             for (int i = 0; i < waiters.Length; i++)
             {
                 this.evt.Set();
-                await waiters[i];
+                await waiters[i].ConfigureAwait(false);
             }
         }
 
@@ -139,7 +139,7 @@ namespace MQTTnet.Core.Tests
             Assert.IsFalse(waitTask.IsCompleted);
 
             // Cancel the request and ensure that it propagates to the task.
-            await Task.Delay(1000);
+            await Task.Delay(1000).ConfigureAwait(false);
             try
             {
                 waitTask.GetAwaiter().GetResult();