diff --git a/FollowingFileStream.APIdoc/docfx.json b/FollowingFileStream.APIdoc/docfx.json
index 269d171..868ac7e 100644
--- a/FollowingFileStream.APIdoc/docfx.json
+++ b/FollowingFileStream.APIdoc/docfx.json
@@ -17,7 +17,7 @@
       "disableGitFeatures": false,
       "disableDefaultFilter": false,
       "properties": {
-        "TargetFramework": "netstandard2.0"
+        "TargetFramework": "netstandard2.1"
       }
     }
   ],
diff --git a/FollowingFileStream.ConsoleTestTool/FollowingFileStream.ConsoleTestTool.csproj b/FollowingFileStream.ConsoleTestTool/FollowingFileStream.ConsoleTestTool.csproj
index c35198b..23d755e 100644
--- a/FollowingFileStream.ConsoleTestTool/FollowingFileStream.ConsoleTestTool.csproj
+++ b/FollowingFileStream.ConsoleTestTool/FollowingFileStream.ConsoleTestTool.csproj
@@ -6,7 +6,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <TargetFrameworks>netcoreapp3.0;netcoreapp2.2</TargetFrameworks>
     <LangVersion>7.1</LangVersion>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
diff --git a/FollowingFileStream.Tests/FollowingFileStream.Tests.csproj b/FollowingFileStream.Tests/FollowingFileStream.Tests.csproj
index 793ab8a..21cdc27 100644
--- a/FollowingFileStream.Tests/FollowingFileStream.Tests.csproj
+++ b/FollowingFileStream.Tests/FollowingFileStream.Tests.csproj
@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.2</TargetFramework>
+    <TargetFrameworks>netcoreapp3.0;netcoreapp2.2</TargetFrameworks>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
   <ItemGroup>
diff --git a/FollowingFileStream/AsyncStream.cs b/FollowingFileStream/AsyncStream.cs
index dcb12c8..134f7b3 100644
--- a/FollowingFileStream/AsyncStream.cs
+++ b/FollowingFileStream/AsyncStream.cs
@@ -9,6 +9,7 @@ namespace Manandre.IO
     /// <summary>
     /// 
     /// </summary>
+    #pragma warning disable S3881
     public abstract class AsyncStream : Stream
     {
 #if !NETSTANDARD1_3
@@ -286,8 +287,28 @@ public sealed override void Write(byte[] buffer, int offset, int count)
         /// </exception>
         public abstract override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken);
 
-        private bool disposed = false;
+#if NETSTANDARD2_1
+        /// <summary>
+        /// Asynchronously releases the unmanaged resources used by the FollowingFileStream and optionally
+        /// releases the managed resources.
+        /// </summary>
+        /// <param name="disposing">true to release both managed and unmanaged resources; false to release only unmanaged resources.
+        ///</param>
+        protected virtual ValueTask DisposeAsync(bool disposing) => default;
+
+        /// <summary>
+        /// Asynchronously releases all resources used by the AsyncStream.
+        /// </summary>
+        public sealed override ValueTask DisposeAsync() => DisposeAsync(true);
 
+        /// <summary>
+        /// Releases the unmanaged resources used by the FollowingFileStream and optionally
+        /// releases the managed resources.
+        /// </summary>
+        /// <param name="disposing">true to release both managed and unmanaged resources; false to release only unmanaged resources.
+        ///</param>
+        protected sealed override void Dispose(bool disposing) => DisposeAsync(disposing).GetAwaiter().GetResult();
+#else        
         /// <summary>
         /// Releases the unmanaged resources used by the FollowingFileStream and optionally
         /// releases the managed resources.
@@ -296,14 +317,10 @@ public sealed override void Write(byte[] buffer, int offset, int count)
         ///</param>
         protected override void Dispose(bool disposing)
         {
-            if (disposed)
-                return;
-
-            disposed = true;
             // Call stream class implementation.
             base.Dispose(disposing);
         }
-
+#endif
         /// <summary>
         /// Synchronized version of an async stream
         /// </summary>
@@ -400,26 +417,6 @@ public override int WriteTimeout
                 }
             }
 
-            protected override void Dispose(bool disposing)
-            {
-                try
-                {
-                    // Explicitly pick up a potentially methodimpl'ed Dispose
-                    if (disposing)
-                    {
-                        cts.Cancel();
-                        using (locker.Lock())
-                        {
-                            ((IDisposable)_stream).Dispose();
-                        }
-                    }
-                }
-                finally
-                {
-                    base.Dispose(disposing);
-                }
-            }
-
             public override long Seek(long offset, SeekOrigin origin)
             {
                 using (locker.Lock(cts.Token))
@@ -481,9 +478,64 @@ public override async Task FlushAsync(CancellationToken cancellationToken)
                     cancellationToken.ThrowIfCancellationRequested();
                 }
             }
+
+            private bool disposed = false;
+
+#if NETSTANDARD2_1
+            protected override async ValueTask DisposeAsync(bool disposing)
+            {
+                if (disposed)
+                    return;
+                
+                try
+                {
+                    // Explicitly pick up a potentially methodimpl'ed DisposeAsync
+                    if (disposing)
+                    {
+                        cts.Cancel();
+                        using (await locker.LockAsync())
+                        {
+                            await ((IAsyncDisposable)_stream).DisposeAsync();
+                        }
+                    }
+                }
+                finally
+                {
+                    disposed = true;
+                    await base.DisposeAsync(disposing);
+                }
+            }
+#else
+            protected override void Dispose(bool disposing)
+            {
+                if (disposed)
+                    return;
+                
+                try
+                {
+                    // Explicitly pick up a potentially methodimpl'ed Dispose
+                    if (disposing)
+                    {
+                        cts.Cancel();
+                        using (locker.Lock())
+                        {
+                            ((IDisposable)_stream).Dispose();
+                        }
+
+                    }
+                }
+                finally
+                {
+                    disposed = true;
+                    base.Dispose(disposing);
+                }
+            }
+#endif
         }
     }
 
+    #pragma warning restore S3881
+
     /// <summary>
     /// AsyncStream class extensions
     /// </summary>
diff --git a/FollowingFileStream/FollowingFileStream.cs b/FollowingFileStream/FollowingFileStream.cs
index c1d6153..d5a3b59 100644
--- a/FollowingFileStream/FollowingFileStream.cs
+++ b/FollowingFileStream/FollowingFileStream.cs
@@ -63,7 +63,9 @@ public class FollowingFileStream : AsyncStream
         /// </exception>
         public FollowingFileStream(string path)
         {
+#pragma warning disable S2930
             fileStream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
+#pragma warning restore S2930
         }
 
         /// <summary>
@@ -120,7 +122,9 @@ public FollowingFileStream(string path)
         /// </exception>
         public FollowingFileStream(string path, int bufferSize, bool useAsync)
         {
+#pragma warning disable S2930
             fileStream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.ReadWrite, bufferSize, useAsync);
+#pragma warning restore S2930
         }
         #endregion
 
@@ -324,8 +328,36 @@ private bool IsFileLockedForWriting()
             return false;
         }
 
-        bool disposed = false;
+        private bool disposed = false;
 
+#if NETSTANDARD2_1
+        /// <summary>
+        /// Releases the unmanaged resources used by the FollowingFileStream and optionally
+        /// releases the managed resources.
+        /// </summary>
+        /// <param name="disposing">true to release both managed and unmanaged resources; false to release only unmanaged resources.
+        ///</param>
+        protected override async ValueTask DisposeAsync(bool disposing)
+        {
+            if (disposed)
+                return;
+
+            try
+            {
+                if (disposing)
+                {
+                    cts.Cancel();
+                    await fileStream.DisposeAsync();
+                }
+            }
+            finally
+            {
+                disposed = true;
+                // Call stream class implementation.
+                base.Dispose(disposing);
+            }
+        }
+#else
         /// <summary>
         /// Releases the unmanaged resources used by the FollowingFileStream and optionally
         /// releases the managed resources.
@@ -347,7 +379,7 @@ protected override void Dispose(bool disposing)
             // Call stream class implementation.
             base.Dispose(disposing);
         }
-
+#endif
         /// <summary>
         /// Clears buffers for this stream and causes any buffered data to be written to the file.
         /// </summary>
diff --git a/FollowingFileStream/FollowingFileStream.csproj b/FollowingFileStream/FollowingFileStream.csproj
index 51ed82b..32c443d 100644
--- a/FollowingFileStream/FollowingFileStream.csproj
+++ b/FollowingFileStream/FollowingFileStream.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <TargetFrameworks>netstandard2.0;netstandard1.3</TargetFrameworks>
+    <TargetFrameworks>netstandard2.1;netstandard2.0;netstandard1.3</TargetFrameworks>
     <DocumentationFile>bin\$(Configuration)\$(TargetFramework)\$(AssemblyName).xml</DocumentationFile>
   </PropertyGroup>
   <PropertyGroup>
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index cac8b84..8bb09ad 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -36,6 +36,16 @@ jobs:
         projectVersion: '$(Build.BuildId)'
         extraProperties: 'sonar.cs.opencover.reportsPaths=$(Build.SourcesDirectory)/coverage/coverage.opencover.xml'
 
+    - task: UseDotNet@2
+      displayName: 'Use dotnet sdk 2.x'
+      inputs:
+        version: 2.x
+        
+    - task: UseDotNet@2
+      displayName: 'Use dotnet sdk 3.x'
+      inputs:
+        version: 3.x
+
     - task: DotNetCoreCLI@2
       displayName: Restore
       inputs:
@@ -158,6 +168,16 @@ jobs:
           command: 'install'
           installPackageId: 'wkhtmltopdf'
       
+      - task: UseDotNet@2
+        displayName: 'Use dotnet sdk 2.x'
+        inputs:
+          version: 2.x
+        
+      - task: UseDotNet@2
+        displayName: 'Use dotnet sdk 3.x'
+        inputs:
+          version: 3.x
+
       # First restore to resolve external dependencies
       - task: DotNetCoreCLI@2
         displayName: Restore
@@ -191,4 +211,4 @@ jobs:
         inputs:
           PathtoPublish: '$(Build.SourcesDirectory)/FollowingFileStream.APIdoc/_site_pdf/FollowingFileStream.APIdoc_pdf.pdf'
           ArtifactName: 'apidoc_pdf'
-          publishLocation: 'Container'
\ No newline at end of file
+          publishLocation: 'Container'