diff --git a/src/System.Runtime.Extensions/System.Runtime.Extensions.sln b/src/System.Runtime.Extensions/System.Runtime.Extensions.sln
index a56140ab8633..4ef1d323a52e 100644
--- a/src/System.Runtime.Extensions/System.Runtime.Extensions.sln
+++ b/src/System.Runtime.Extensions/System.Runtime.Extensions.sln
@@ -40,14 +40,14 @@ Global
 	EndGlobalSection
 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
 		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.Debug|Any CPU.ActiveCfg = Windows_Debug|Any CPU
-		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.net46_Debug|Any CPU.ActiveCfg = net462_Release|Any CPU
-		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.net46_Debug|Any CPU.Build.0 = net462_Release|Any CPU
-		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.net46_Release|Any CPU.ActiveCfg = net462_Release|Any CPU
-		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.net46_Release|Any CPU.Build.0 = net462_Release|Any CPU
-		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.netstandard1.7_Debug|Any CPU.ActiveCfg = net463_Release|Any CPU
-		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.netstandard1.7_Debug|Any CPU.Build.0 = net463_Release|Any CPU
-		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.netstandard1.7_Release|Any CPU.ActiveCfg = net463_Debug|Any CPU
-		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.netstandard1.7_Release|Any CPU.Build.0 = net463_Debug|Any CPU
+		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.net46_Debug|Any CPU.ActiveCfg = net461_Release|Any CPU
+		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.net46_Debug|Any CPU.Build.0 = net461_Release|Any CPU
+		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.net46_Release|Any CPU.ActiveCfg = net461_Release|Any CPU
+		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.net46_Release|Any CPU.Build.0 = net461_Release|Any CPU
+		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.netstandard1.7_Debug|Any CPU.ActiveCfg = net461_Release|Any CPU
+		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.netstandard1.7_Debug|Any CPU.Build.0 = net461_Release|Any CPU
+		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.netstandard1.7_Release|Any CPU.ActiveCfg = net461_Release|Any CPU
+		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.netstandard1.7_Release|Any CPU.Build.0 = net461_Release|Any CPU
 		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.Release|Any CPU.ActiveCfg = Windows_Release|Any CPU
 		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.Unix_Debug|Any CPU.ActiveCfg = Unix_Debug|Any CPU
 		{845D2B72-D8A4-42E5-9BE9-17639EC4FC1A}.Unix_Debug|Any CPU.Build.0 = Unix_Debug|Any CPU
diff --git a/src/System.Runtime.Extensions/ref/System.Runtime.Extensions.cs b/src/System.Runtime.Extensions/ref/System.Runtime.Extensions.cs
index d5d8c1d14ec4..5d6bc798e03f 100644
--- a/src/System.Runtime.Extensions/ref/System.Runtime.Extensions.cs
+++ b/src/System.Runtime.Extensions/ref/System.Runtime.Extensions.cs
@@ -901,6 +901,9 @@ protected StringComparer() { }
         public static System.StringComparer InvariantCultureIgnoreCase { get { throw null; } }
         public static System.StringComparer Ordinal { get { throw null; } }
         public static System.StringComparer OrdinalIgnoreCase { get { throw null; } }
+#if netcoreapp11
+        public static System.StringComparer FromComparison(System.StringComparison comparisonType) { throw null; }
+#endif
         public abstract int Compare(string x, string y);
         public static System.StringComparer Create(System.Globalization.CultureInfo culture, bool ignoreCase) { throw null; }
         public new bool Equals(object x, object y) { throw null; }
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 ffdffdc7a863..ffa081346231 100644
--- a/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj
+++ b/src/System.Runtime.Extensions/tests/System.Runtime.Extensions.Tests.csproj
@@ -55,6 +55,7 @@
     <Compile Include="System\IO\Path.GetRelativePath.cs" />
     <Compile Include="System\MathTests.netcoreapp1.1.cs" />
     <Compile Include="System\MathF.netcoreapp1.1.cs" />
+    <Compile Include="System\StringComparer.netcoreapp1.1.cs" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="System\Diagnostics\Stopwatch.cs" />
diff --git a/src/System.Runtime.Extensions/tests/System/StringComparer.netcoreapp1.1.cs b/src/System.Runtime.Extensions/tests/System/StringComparer.netcoreapp1.1.cs
new file mode 100644
index 000000000000..ed8ced4f10a5
--- /dev/null
+++ b/src/System.Runtime.Extensions/tests/System/StringComparer.netcoreapp1.1.cs
@@ -0,0 +1,42 @@
+// 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.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using Xunit;
+
+namespace System.Tests
+{
+    public static partial class MiscStringComparerTests
+    {
+        public static readonly object[][] FromComparison_TestData =
+        {
+            //              StringComparison                StringComparer
+            new object[] { StringComparison.CurrentCulture, StringComparer.CurrentCulture },
+            new object[] { StringComparison.CurrentCultureIgnoreCase, StringComparer.CurrentCultureIgnoreCase },
+            new object[] { StringComparison.InvariantCulture, StringComparer.InvariantCulture },
+            new object[] { StringComparison.InvariantCultureIgnoreCase, StringComparer.InvariantCultureIgnoreCase },
+            new object[] { StringComparison.Ordinal, StringComparer.Ordinal },
+            new object[] { StringComparison.OrdinalIgnoreCase, StringComparer.OrdinalIgnoreCase },
+        };
+
+        [Theory]
+        [MemberData(nameof(FromComparison_TestData))]
+        public static void FromComparisonTest(StringComparison comparison, StringComparer comparer)
+        {
+            Assert.Equal(comparer, StringComparer.FromComparison(comparison));
+        }
+
+        [Fact]
+        public static void FromComparisonInvalidTest()
+        {
+            StringComparison minInvalid = Enum.GetValues(typeof(StringComparison)).Cast<StringComparison>().Min() - 1;
+            StringComparison maxInvalid = Enum.GetValues(typeof(StringComparison)).Cast<StringComparison>().Max() + 1;
+
+            Assert.Throws<ArgumentException>(() => StringComparer.FromComparison(minInvalid));
+            Assert.Throws<ArgumentException>(() => StringComparer.FromComparison(maxInvalid));
+        }
+    }
+}
diff --git a/src/System.Runtime.Extensions/tests/System/StringComparer.netstandard1.7.cs b/src/System.Runtime.Extensions/tests/System/StringComparer.netstandard1.7.cs
index ba9fece11d56..d01fd232765d 100644
--- a/src/System.Runtime.Extensions/tests/System/StringComparer.netstandard1.7.cs
+++ b/src/System.Runtime.Extensions/tests/System/StringComparer.netstandard1.7.cs
@@ -8,7 +8,7 @@
 
 namespace System.Tests
 {
-    public static class MiscStringComparerTests
+    public static partial class MiscStringComparerTests
     {
         public static IEnumerable<object[]> UpperLowerCasing_TestData()
         {