diff --git a/build/dependencies.props b/build/dependencies.props
index 3c71bd378d..4e451e9dc7 100644
--- a/build/dependencies.props
+++ b/build/dependencies.props
@@ -3,6 +3,7 @@
     <AspNetCoreVersion>2.1.0-*</AspNetCoreVersion>
     <CoreFxVersion>4.4.0-*</CoreFxVersion>
     <InternalAspNetCoreSdkVersion>2.1.1-*</InternalAspNetCoreSdkVersion>
+    <MoqVersion>4.7.49</MoqVersion>
     <NETStandardImplicitPackageVersion>2.0.0-*</NETStandardImplicitPackageVersion>
     <NETStandardLibraryNETFrameworkVersion>2.0.0-*</NETStandardLibraryNETFrameworkVersion>
     <RuntimeFrameworkVersion Condition="'$(TargetFramework)'=='netcoreapp2.0'">2.0.0-*</RuntimeFrameworkVersion>
diff --git a/src/Microsoft.AspNetCore.WebUtilities/HttpRequestStreamReader.cs b/src/Microsoft.AspNetCore.WebUtilities/HttpRequestStreamReader.cs
index 24ee35936c..3f9478c5de 100644
--- a/src/Microsoft.AspNetCore.WebUtilities/HttpRequestStreamReader.cs
+++ b/src/Microsoft.AspNetCore.WebUtilities/HttpRequestStreamReader.cs
@@ -32,6 +32,7 @@ namespace Microsoft.AspNetCore.WebUtilities
         private int _bytesRead;
 
         private bool _isBlocked;
+        private bool _disposed;
 
         public HttpRequestStreamReader(Stream stream, Encoding encoding)
             : this(stream, encoding, DefaultBufferSize, ArrayPool<byte>.Shared, ArrayPool<char>.Shared)
@@ -50,44 +51,23 @@ namespace Microsoft.AspNetCore.WebUtilities
             ArrayPool<byte> bytePool,
             ArrayPool<char> charPool)
         {
-            if (stream == null)
-            {
-                throw new ArgumentNullException(nameof(stream));
-            }
-
-            if (!stream.CanRead)
-            {
-                throw new ArgumentException(Resources.HttpRequestStreamReader_StreamNotReadable, nameof(stream));
-            }
-
-            if (encoding == null)
-            {
-                throw new ArgumentNullException(nameof(encoding));
-            }
-
-            if (bytePool == null)
-            {
-                throw new ArgumentNullException(nameof(bytePool));
-            }
-
-            if (charPool == null)
-            {
-                throw new ArgumentNullException(nameof(charPool));
-            }
+            _stream = stream ?? throw new ArgumentNullException(nameof(stream));
+            _encoding = encoding ?? throw new ArgumentNullException(nameof(encoding));
+            _bytePool = bytePool ?? throw new ArgumentNullException(nameof(bytePool));
+            _charPool = charPool ?? throw new ArgumentNullException(nameof(charPool));
 
             if (bufferSize <= 0)
             {
                 throw new ArgumentOutOfRangeException(nameof(bufferSize));
             }
+            if (!stream.CanRead)
+            {
+                throw new ArgumentException(Resources.HttpRequestStreamReader_StreamNotReadable, nameof(stream));
+            }
 
-            _stream = stream;
-            _encoding = encoding;
             _byteBufferSize = bufferSize;
-            _bytePool = bytePool;
-            _charPool = charPool;
 
             _decoder = encoding.GetDecoder();
-
             _byteBuffer = _bytePool.Rent(bufferSize);
 
             try
@@ -98,33 +78,24 @@ namespace Microsoft.AspNetCore.WebUtilities
             catch
             {
                 _bytePool.Return(_byteBuffer);
-                _byteBuffer = null;
 
                 if (_charBuffer != null)
                 {
                     _charPool.Return(_charBuffer);
-                    _charBuffer = null;
                 }
+
+                throw;
             }
         }
 
         protected override void Dispose(bool disposing)
         {
-            if (disposing && _stream != null)
+            if (disposing && !_disposed)
             {
-                _stream = null;
+                _disposed = true;
 
-                if (_bytePool != null)
-                {
-                    _bytePool.Return(_byteBuffer);
-                    _byteBuffer = null;
-                }
-
-                if (_charPool != null)
-                {
-                    _charPool.Return(_charBuffer);
-                    _charBuffer = null;
-                }
+                _bytePool.Return(_byteBuffer);
+                _charPool.Return(_charBuffer);
             }
 
             base.Dispose(disposing);
@@ -132,9 +103,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override int Peek()
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpRequestStreamReader));
             }
 
             if (_charBufferIndex == _charsRead)
@@ -150,9 +121,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override int Read()
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpRequestStreamReader));
             }
 
             if (_charBufferIndex == _charsRead)
@@ -183,9 +154,9 @@ namespace Microsoft.AspNetCore.WebUtilities
                 throw new ArgumentOutOfRangeException(nameof(count));
             }
 
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpRequestStreamReader));
             }
 
             var charsRead = 0;
@@ -246,9 +217,9 @@ namespace Microsoft.AspNetCore.WebUtilities
                 throw new ArgumentOutOfRangeException(nameof(count));
             }
 
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpRequestStreamReader));
             }
 
             if (_charBufferIndex == _charsRead && await ReadIntoBufferAsync() == 0)
diff --git a/src/Microsoft.AspNetCore.WebUtilities/HttpResponseStreamWriter.cs b/src/Microsoft.AspNetCore.WebUtilities/HttpResponseStreamWriter.cs
index 4356693d58..050088ccb7 100644
--- a/src/Microsoft.AspNetCore.WebUtilities/HttpResponseStreamWriter.cs
+++ b/src/Microsoft.AspNetCore.WebUtilities/HttpResponseStreamWriter.cs
@@ -28,6 +28,7 @@ namespace Microsoft.AspNetCore.WebUtilities
         private char[] _charBuffer;
 
         private int _charBufferCount;
+        private bool _disposed;
 
         public HttpResponseStreamWriter(Stream stream, Encoding encoding)
             : this(stream, encoding, DefaultBufferSize, ArrayPool<byte>.Shared, ArrayPool<char>.Shared)
@@ -46,15 +47,19 @@ namespace Microsoft.AspNetCore.WebUtilities
             ArrayPool<byte> bytePool,
             ArrayPool<char> charPool)
         {
-            if (!stream.CanWrite)
-            {
-                throw new ArgumentException(Resources.HttpResponseStreamWriter_StreamNotWritable, nameof(stream));
-            }
-
+            _stream = stream ?? throw new ArgumentNullException(nameof(stream));
             Encoding = encoding ?? throw new ArgumentNullException(nameof(encoding));
             _bytePool = bytePool ?? throw new ArgumentNullException(nameof(bytePool));
             _charPool = charPool ?? throw new ArgumentNullException(nameof(charPool));
-            _stream = stream ?? throw new ArgumentNullException(nameof(stream));
+
+            if (bufferSize <= 0)
+            {
+                throw new ArgumentOutOfRangeException(nameof(bufferSize));
+            }
+            if (!_stream.CanWrite)
+            {
+                throw new ArgumentException(Resources.HttpResponseStreamWriter_StreamNotWritable, nameof(stream));
+            }
 
             _charBufferSize = bufferSize;
 
@@ -69,12 +74,10 @@ namespace Microsoft.AspNetCore.WebUtilities
             catch
             {
                 charPool.Return(_charBuffer);
-                _charBuffer = null;
 
                 if (_byteBuffer != null)
                 {
                     bytePool.Return(_byteBuffer);
-                    _byteBuffer = null;
                 }
 
                 throw;
@@ -85,9 +88,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override void Write(char value)
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpResponseStreamWriter));
             }
 
             if (_charBufferCount == _charBufferSize)
@@ -101,9 +104,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override void Write(char[] values, int index, int count)
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpResponseStreamWriter));
             }
 
             if (values == null)
@@ -124,9 +127,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override void Write(string value)
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpResponseStreamWriter));
             }
 
             if (value == null)
@@ -149,9 +152,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override async Task WriteAsync(char value)
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpResponseStreamWriter));
             }
 
             if (_charBufferCount == _charBufferSize)
@@ -165,9 +168,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override async Task WriteAsync(char[] values, int index, int count)
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpResponseStreamWriter));
             }
 
             if (values == null)
@@ -188,9 +191,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override async Task WriteAsync(string value)
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpResponseStreamWriter));
             }
 
             if (value == null)
@@ -216,9 +219,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override void Flush()
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpResponseStreamWriter));
             }
 
             FlushInternal(flushEncoder: true);
@@ -226,9 +229,9 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         public override Task FlushAsync()
         {
-            if (_stream == null)
+            if (_disposed)
             {
-                throw new ObjectDisposedException("stream");
+                throw new ObjectDisposedException(nameof(HttpResponseStreamWriter));
             }
 
             return FlushInternalAsync(flushEncoder: true);
@@ -236,29 +239,21 @@ namespace Microsoft.AspNetCore.WebUtilities
 
         protected override void Dispose(bool disposing)
         {
-            if (disposing && _stream != null)
+            if (disposing && !_disposed)
             {
+                _disposed = true;
                 try
                 {
                     FlushInternal(flushEncoder: true);
                 }
                 finally
                 {
-                    _stream = null;
-
-                    if (_bytePool != null)
-                    {
-                        _bytePool.Return(_byteBuffer);
-                        _byteBuffer = null;
-                    }
-
-                    if (_charPool != null)
-                    {
-                        _charPool.Return(_charBuffer);
-                        _charBuffer = null;
-                    }
+                    _bytePool.Return(_byteBuffer);
+                    _charPool.Return(_charBuffer);
                 }
             }
+
+            base.Dispose(disposing);
         }
 
         // Note: our FlushInternal method does NOT flush the underlying stream. This would result in
diff --git a/test/Microsoft.AspNetCore.WebUtilities.Tests/HttpRequestStreamReaderTest.cs b/test/Microsoft.AspNetCore.WebUtilities.Tests/HttpRequestStreamReaderTest.cs
index 82163c2b54..ee4d2f2bdc 100644
--- a/test/Microsoft.AspNetCore.WebUtilities.Tests/HttpRequestStreamReaderTest.cs
+++ b/test/Microsoft.AspNetCore.WebUtilities.Tests/HttpRequestStreamReaderTest.cs
@@ -1,12 +1,16 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using Moq;
+using System;
+using System.Buffers;
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
 using System.Threading.Tasks;
 using Xunit;
 
+
 namespace Microsoft.AspNetCore.WebUtilities.Test
 {
     public class HttpResponseStreamReaderTest
@@ -191,6 +195,64 @@ namespace Microsoft.AspNetCore.WebUtilities.Test
             Assert.Null(eol);
         }
 
+        [Theory]
+        [MemberData(nameof(HttpRequestNullData))]
+        public static void NullInputsInConstructor_ExpectArgumentNullException(Stream stream, Encoding encoding, ArrayPool<byte> bytePool, ArrayPool<char> charPool)
+        {
+            Assert.Throws<ArgumentNullException>(() =>
+            {
+                var httpRequestStreamReader = new HttpRequestStreamReader(stream, encoding, 1, bytePool, charPool);
+            });
+        }
+
+
+
+        [Theory]
+        [InlineData(0)]
+        [InlineData(-1)]
+        public static void NegativeOrZeroBufferSize_ExpectArgumentOutOfRangeException(int size)
+        {
+            Assert.Throws<ArgumentOutOfRangeException>(() =>
+            {
+                var httpRequestStreamReader = new HttpRequestStreamReader(new MemoryStream(), Encoding.UTF8, size, ArrayPool<byte>.Shared, ArrayPool<char>.Shared);
+            });
+        }
+
+        [Fact]
+        public static void StreamCannotRead_ExpectArgumentException()
+        {
+            var mockStream = new Mock<Stream>();
+            mockStream.Setup(m => m.CanRead).Returns(false);
+            Assert.Throws<ArgumentException>(() =>
+            {
+                var httpRequestStreamReader = new HttpRequestStreamReader(mockStream.Object, Encoding.UTF8, 1, ArrayPool<byte>.Shared, ArrayPool<char>.Shared);
+            });
+        }
+
+        [Theory]
+        [MemberData(nameof(HttpRequestDisposeData))]
+        public static void StreamDisposed_ExpectedObjectDisposedException(Action<HttpRequestStreamReader> action)
+        {
+            var httpRequestStreamReader = new HttpRequestStreamReader(new MemoryStream(), Encoding.UTF8, 10, ArrayPool<byte>.Shared, ArrayPool<char>.Shared);
+            httpRequestStreamReader.Dispose();
+
+            Assert.Throws<ObjectDisposedException>(() =>
+            {
+                action(httpRequestStreamReader);
+            });
+        }
+
+        [Fact]
+        public static async Task StreamDisposed_ExpectObjectDisposedExceptionAsync()
+        {
+            var httpRequestStreamReader = new HttpRequestStreamReader(new MemoryStream(), Encoding.UTF8, 10, ArrayPool<byte>.Shared, ArrayPool<char>.Shared);
+            httpRequestStreamReader.Dispose();
+
+            await Assert.ThrowsAsync<ObjectDisposedException>(() =>
+            {
+                return httpRequestStreamReader.ReadAsync(new char[10], 0, 1);
+            });
+        }
         private static HttpRequestStreamReader CreateReader()
         {
             var stream = new MemoryStream();
@@ -221,5 +283,30 @@ namespace Microsoft.AspNetCore.WebUtilities.Test
 
             return new MemoryStream(data.ToArray());
         }
+        private static IEnumerable<object[]> HttpRequestNullData()
+        {
+            yield return new object[] { null, Encoding.UTF8, ArrayPool<byte>.Shared, ArrayPool<char>.Shared };
+            yield return new object[] { new MemoryStream(), null, ArrayPool<byte>.Shared, ArrayPool<char>.Shared };
+            yield return new object[] { new MemoryStream(), Encoding.UTF8, null, ArrayPool<char>.Shared };
+            yield return new object[] { new MemoryStream(), Encoding.UTF8, ArrayPool<byte>.Shared, null };
+        }
+
+        private static IEnumerable<object[]> HttpRequestDisposeData()
+        {
+            yield return new object[] { new Action<HttpRequestStreamReader>((httpRequestStreamReader) =>
+            {
+                 var res = httpRequestStreamReader.Read();
+            })};
+            yield return new object[] { new Action<HttpRequestStreamReader>((httpRequestStreamReader) =>
+            {
+                 var res = httpRequestStreamReader.Read(new char[10], 0, 1);
+            })};
+
+            yield return new object[] { new Action<HttpRequestStreamReader>((httpRequestStreamReader) =>
+            {
+                var res = httpRequestStreamReader.Peek();
+            })};
+
+        }
     }
 }
diff --git a/test/Microsoft.AspNetCore.WebUtilities.Tests/HttpResponseStreamWriterTest.cs b/test/Microsoft.AspNetCore.WebUtilities.Tests/HttpResponseStreamWriterTest.cs
index 10bd4bda3f..d0c94f9739 100644
--- a/test/Microsoft.AspNetCore.WebUtilities.Tests/HttpResponseStreamWriterTest.cs
+++ b/test/Microsoft.AspNetCore.WebUtilities.Tests/HttpResponseStreamWriterTest.cs
@@ -1,8 +1,10 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using Moq;
 using System;
 using System.Buffers;
+using System.Collections.Generic;
 using System.IO;
 using System.Text;
 using System.Threading;
@@ -405,6 +407,65 @@ namespace Microsoft.AspNetCore.WebUtilities.Test
             Assert.Equal(content, actualContent);
         }
 
+        [Theory]
+        [MemberData(nameof(HttpResponseStreamWriterData))]
+        public static void NullInputsInConstructor_ExpectArgumentNullException(Stream stream, Encoding encoding, ArrayPool<byte> bytePool, ArrayPool<char> charPool)
+        {
+            Assert.Throws<ArgumentNullException>(() =>
+            {
+                var httpRequestStreamReader = new HttpResponseStreamWriter(stream, encoding, 1, bytePool, charPool);
+            });
+        }
+
+        [Theory]
+        [InlineData(0)]
+        [InlineData(-1)]
+        public static void NegativeOrZeroBufferSize_ExpectArgumentOutOfRangeException(int size)
+        {
+            Assert.Throws<ArgumentOutOfRangeException>(() =>
+            {
+                var httpRequestStreamReader = new HttpRequestStreamReader(new MemoryStream(), Encoding.UTF8, size, ArrayPool<byte>.Shared, ArrayPool<char>.Shared);
+            });
+        }
+
+        [Fact]
+        public static void StreamCannotRead_ExpectArgumentException()
+        {
+            var mockStream = new Mock<Stream>();
+            mockStream.Setup(m => m.CanWrite).Returns(false);
+            Assert.Throws<ArgumentException>(() =>
+            {
+                var httpRequestStreamReader = new HttpRequestStreamReader(mockStream.Object, Encoding.UTF8, 1, ArrayPool<byte>.Shared, ArrayPool<char>.Shared);
+            });
+        }
+
+        [Theory]
+        [MemberData(nameof(HttpResponseDisposeData))]
+        public static void StreamDisposed_ExpectedObjectDisposedException(Action<HttpResponseStreamWriter> action)
+        {
+            var httpResponseStreamWriter = new HttpResponseStreamWriter(new MemoryStream(), Encoding.UTF8, 10, ArrayPool<byte>.Shared, ArrayPool<char>.Shared);
+            httpResponseStreamWriter.Dispose();
+
+            Assert.Throws<ObjectDisposedException>(() =>
+            {
+                action(httpResponseStreamWriter);
+            });
+        }
+
+        [Theory]
+        [MemberData(nameof(HttpResponseDisposeDataAsync))]
+        public static async Task StreamDisposed_ExpectedObjectDisposedExceptionAsync(Func<HttpResponseStreamWriter, Task> function)
+        {
+            var httpResponseStreamWriter = new HttpResponseStreamWriter(new MemoryStream(), Encoding.UTF8, 10, ArrayPool<byte>.Shared, ArrayPool<char>.Shared);
+            httpResponseStreamWriter.Dispose();
+
+            await Assert.ThrowsAsync<ObjectDisposedException>(() =>
+            {
+                 return function(httpResponseStreamWriter);
+            });
+        }
+
+
         private class TestMemoryStream : MemoryStream
         {
             public int FlushCallCount { get; private set; }
@@ -459,5 +520,54 @@ namespace Microsoft.AspNetCore.WebUtilities.Test
                 base.Dispose(disposing);
             }
         }
+
+        private static IEnumerable<object[]> HttpResponseStreamWriterData()
+        {
+            yield return new object[] { null, Encoding.UTF8, ArrayPool<byte>.Shared, ArrayPool<char>.Shared };
+            yield return new object[] { new MemoryStream(), null, ArrayPool<byte>.Shared, ArrayPool<char>.Shared };
+            yield return new object[] { new MemoryStream(), Encoding.UTF8, null, ArrayPool<char>.Shared };
+            yield return new object[] { new MemoryStream(), Encoding.UTF8, ArrayPool<byte>.Shared, null };
+        }
+
+        private static IEnumerable<object[]> HttpResponseDisposeData()
+        {
+            yield return new object[] { new Action<HttpResponseStreamWriter>((httpResponseStreamWriter) =>
+            {
+                 httpResponseStreamWriter.Write('a');
+            })};
+            yield return new object[] { new Action<HttpResponseStreamWriter>((httpResponseStreamWriter) =>
+            {
+                 httpResponseStreamWriter.Write(new char[] { 'a', 'b' }, 0, 1);
+            })};
+
+            yield return new object[] { new Action<HttpResponseStreamWriter>((httpResponseStreamWriter) =>
+            {
+                httpResponseStreamWriter.Write("hello");
+            })};
+            yield return new object[] { new Action<HttpResponseStreamWriter>((httpResponseStreamWriter) =>
+            {
+                httpResponseStreamWriter.Flush();
+            })};
+        }
+        private static IEnumerable<object[]> HttpResponseDisposeDataAsync()
+        {
+            yield return new object[] { new Func<HttpResponseStreamWriter, Task>(async (httpResponseStreamWriter) =>
+            {
+                await httpResponseStreamWriter.WriteAsync('a');
+            })};
+            yield return new object[] { new Func<HttpResponseStreamWriter, Task>(async (httpResponseStreamWriter) =>
+            {
+                await httpResponseStreamWriter.WriteAsync(new char[] { 'a', 'b' }, 0, 1);
+            })};
+
+            yield return new object[] { new Func<HttpResponseStreamWriter, Task>(async (httpResponseStreamWriter) =>
+            {
+                await httpResponseStreamWriter.WriteAsync("hello");
+            })};
+            yield return new object[] { new Func<HttpResponseStreamWriter, Task>(async (httpResponseStreamWriter) =>
+            {
+                await httpResponseStreamWriter.FlushAsync();
+            })};
+        }
     }
 }
diff --git a/test/Microsoft.AspNetCore.WebUtilities.Tests/Microsoft.AspNetCore.WebUtilities.Tests.csproj b/test/Microsoft.AspNetCore.WebUtilities.Tests/Microsoft.AspNetCore.WebUtilities.Tests.csproj
index c37aac336e..66a940aed2 100644
--- a/test/Microsoft.AspNetCore.WebUtilities.Tests/Microsoft.AspNetCore.WebUtilities.Tests.csproj
+++ b/test/Microsoft.AspNetCore.WebUtilities.Tests/Microsoft.AspNetCore.WebUtilities.Tests.csproj
@@ -13,6 +13,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(TestSdkVersion)" />
+    <PackageReference Include="Moq" Version="$(MoqVersion)" />
     <PackageReference Include="xunit.runner.visualstudio" Version="$(XunitVersion)" />
     <PackageReference Include="xunit" Version="$(XunitVersion)" />
   </ItemGroup>