diff --git a/src/System.Runtime.Extensions/ref/System.Runtime.Extensions.cs b/src/System.Runtime.Extensions/ref/System.Runtime.Extensions.cs
index 6d4e39e614b0..d5d8c1d14ec4 100644
--- a/src/System.Runtime.Extensions/ref/System.Runtime.Extensions.cs
+++ b/src/System.Runtime.Extensions/ref/System.Runtime.Extensions.cs
@@ -1532,7 +1532,9 @@ namespace System.Net
     public static partial class WebUtility
     {
         public static string HtmlDecode(string value) { throw null; }
+        public static void HtmlDecode(string value, System.IO.TextWriter output) { }
         public static string HtmlEncode(string value) { throw null; }
+        public static void HtmlEncode(string value, System.IO.TextWriter output) { }
         public static string UrlDecode(string encodedValue) { throw null; }
         public static byte[] UrlDecodeToBytes(byte[] encodedValue, int offset, int count) { throw null; }
         public static string UrlEncode(string value) { throw null; }
diff --git a/src/System.Runtime.Extensions/src/System/Net/WebUtility.cs b/src/System.Runtime.Extensions/src/System/Net/WebUtility.cs
index 3f69ab0aca0f..96ec4c6e92cb 100644
--- a/src/System.Runtime.Extensions/src/System/Net/WebUtility.cs
+++ b/src/System.Runtime.Extensions/src/System/Net/WebUtility.cs
@@ -33,7 +33,7 @@ public static class WebUtility
 
         public static string HtmlEncode(string value)
         {
-            if (String.IsNullOrEmpty(value))
+            if (string.IsNullOrEmpty(value))
             {
                 return value;
             }
@@ -50,6 +50,11 @@ public static string HtmlEncode(string value)
             return StringBuilderCache.GetStringAndRelease(sb);
         }
 
+        public static void HtmlEncode(string value, TextWriter output)
+        {
+            output.Write(HtmlEncode(value));
+        }
+
         private static unsafe void HtmlEncode(string value, int index, StringBuilder output)
         {
             Debug.Assert(value != null);
@@ -138,7 +143,7 @@ private static unsafe void HtmlEncode(string value, int index, StringBuilder out
 
         public static string HtmlDecode(string value)
         {
-            if (String.IsNullOrEmpty(value))
+            if (string.IsNullOrEmpty(value))
             {
                 return value;
             }
@@ -154,6 +159,11 @@ public static string HtmlDecode(string value)
             return StringBuilderCache.GetStringAndRelease(sb);
         }
 
+        public static void HtmlDecode(string value, TextWriter output)
+        {
+            output.Write(HtmlDecode(value));
+        }
+
         [SuppressMessage("Microsoft.Usage", "CA1806:DoNotIgnoreMethodResults", MessageId = "System.UInt16.TryParse(System.String,System.Globalization.NumberStyles,System.IFormatProvider,System.UInt16@)", Justification = "UInt16.TryParse guarantees that result is zero if the parse fails.")]
         private static void HtmlDecode(string value, StringBuilder output)
         {
diff --git a/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj b/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj
index 598d3eb832f4..048b3eb09aab 100644
--- a/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj
+++ b/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj
@@ -43,6 +43,7 @@
     <Compile Include="System\StringComparer.netstandard1.7.cs" />
     <Compile Include="System\Runtime\Versioning\VersioningHelperTests.cs" />
     <Compile Include="System\AppDomainTests.cs" />
+    <Compile Include="System\Net\WebUtility.netstandard1.7.cs" />
     <Compile Include="$(CommonTestPath)\System\Runtime\Serialization\Formatters\BinaryFormatterHelpers.cs">
       <Link>Common\System\Runtime\Serialization\Formatters\BinaryFormatterHelpers.cs</Link>
     </Compile>
diff --git a/src/System.Runtime.Extensions/tests/System/Net/WebUtility.cs b/src/System.Runtime.Extensions/tests/System/Net/WebUtility.cs
index da8df3199d9a..6948b14aa844 100644
--- a/src/System.Runtime.Extensions/tests/System/Net/WebUtility.cs
+++ b/src/System.Runtime.Extensions/tests/System/Net/WebUtility.cs
@@ -4,12 +4,14 @@
 
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Globalization;
+using System.IO;
 using System.Text;
 using Xunit;
 
 namespace System.Net.Tests
 {
-    public class WebUtilityTests
+    public partial class WebUtilityTests
     {
         // HtmlEncode + HtmlDecode
         public static IEnumerable<object[]> HtmlDecode_TestData()
diff --git a/src/System.Runtime.Extensions/tests/System/Net/WebUtility.netstandard1.7.cs b/src/System.Runtime.Extensions/tests/System/Net/WebUtility.netstandard1.7.cs
new file mode 100644
index 000000000000..b5dc8d3972ce
--- /dev/null
+++ b/src/System.Runtime.Extensions/tests/System/Net/WebUtility.netstandard1.7.cs
@@ -0,0 +1,35 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Globalization;
+using System.IO;
+using Xunit;
+
+namespace System.Net.Tests
+{
+    public partial class WebUtilityTests
+    {
+        [Theory]
+        [MemberData(nameof(HtmlDecode_TestData))]
+        public static void HtmlDecode_TextWriterOutput(string value, string expected)
+        {
+            if(value == null)
+                expected = string.Empty;
+            StringWriter output = new StringWriter(CultureInfo.InvariantCulture);
+            WebUtility.HtmlDecode(value, output);
+            Assert.Equal(expected, output.ToString());
+        }
+
+        [Theory]
+        [MemberData(nameof(HtmlEncode_TestData))]
+        public static void HtmlEncode_TextWriterOutput(string value, string expected)
+        {
+            if(value == null)
+                expected = string.Empty;
+            StringWriter output = new StringWriter(CultureInfo.InvariantCulture);
+            WebUtility.HtmlEncode(value, output);
+            Assert.Equal(expected, output.ToString());
+        }
+    }
+}