diff --git a/src/CultureInfoGenerator/Program.cs b/src/CultureInfoGenerator/Program.cs
index 9408009462..76882d3ce0 100644
--- a/src/CultureInfoGenerator/Program.cs
+++ b/src/CultureInfoGenerator/Program.cs
@@ -34,6 +34,7 @@ namespace CultureInfoGenerator
 // *************************** THIS FILE IS GENERATED BY A TOOL ***************************
 // To make changes to this file look at the CultureInfoGenerator project in this solution.
 
+using System;
 using System.Collections.Generic;
 
 namespace Microsoft.Extensions.Globalization
@@ -49,7 +50,7 @@ namespace Microsoft.Extensions.Globalization
         /// As new versions of .NET Framework and Windows are released, this list should be regenerated to ensure it
         /// contains the latest culture names.
         /// </summary>
-        public static readonly HashSet<string> KnownCultureNames = new HashSet<string>
+        public static readonly HashSet<string> KnownCultureNames = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
         {{"
             );
 
diff --git a/src/Microsoft.Extensions.Globalization.CultureInfoCache/CultureInfoList.cs b/src/Microsoft.Extensions.Globalization.CultureInfoCache/CultureInfoList.cs
index 64cd81db0f..29c02b0e5c 100644
--- a/src/Microsoft.Extensions.Globalization.CultureInfoCache/CultureInfoList.cs
+++ b/src/Microsoft.Extensions.Globalization.CultureInfoCache/CultureInfoList.cs
@@ -4,6 +4,7 @@
 // *************************** THIS FILE IS GENERATED BY A TOOL ***************************
 // To make changes to this file look at the CultureInfoGenerator project in this solution.
 
+using System;
 using System.Collections.Generic;
 
 namespace Microsoft.Extensions.Globalization
@@ -19,7 +20,7 @@ namespace Microsoft.Extensions.Globalization
         /// As new versions of .NET Framework and Windows are released, this list should be regenerated to ensure it
         /// contains the latest culture names.
         /// </summary>
-        public static readonly HashSet<string> KnownCultureNames = new HashSet<string>
+        public static readonly HashSet<string> KnownCultureNames = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
         {
             "",
             "af",
diff --git a/test/Microsoft.AspNet.Localization.Tests/QueryStringRequestCultureProviderTest.cs b/test/Microsoft.AspNet.Localization.Tests/QueryStringRequestCultureProviderTest.cs
index 39fc682f8f..f9229864c5 100644
--- a/test/Microsoft.AspNet.Localization.Tests/QueryStringRequestCultureProviderTest.cs
+++ b/test/Microsoft.AspNet.Localization.Tests/QueryStringRequestCultureProviderTest.cs
@@ -167,5 +167,31 @@ namespace Microsoft.Extensions.Localization.Tests
                 var response = await client.GetAsync("/page?c=ar-SA&uic=ar-YE");
             }
         }
+        
+        [Fact]
+        public async void GetTheRightCultureInfoRegardlessOfCultureNameCasing()
+        {
+            using (var server = TestServer.Create(app =>
+            {
+                var options = new RequestLocalizationOptions();
+                var provider = new QueryStringRequestCultureProvider();
+                provider.QueryStringKey = "c";
+                provider.UIQueryStringKey = "uic";
+                options.RequestCultureProviders.Insert(0, provider);
+                app.UseRequestLocalization(options);
+                app.Run(context =>
+                {
+                    var requestCultureFeature = context.Features.Get<IRequestCultureFeature>();
+                    var requestCulture = requestCultureFeature.RequestCulture;
+                    Assert.Equal("fr", requestCulture.Culture.ToString());
+                    Assert.Equal("fr", requestCulture.UICulture.ToString());
+                    return Task.FromResult(0);
+                });
+            }))
+            {
+                var client = server.CreateClient();
+                var response = await client.GetAsync("/page?c=FR&uic=FR");
+            }
+        }
     }
 }
\ No newline at end of file