diff --git a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormCollectionModelBinder.cs b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormCollectionModelBinder.cs
index f4d96087b7..8d30f3268d 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormCollectionModelBinder.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormCollectionModelBinder.cs
@@ -109,6 +109,12 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 return null;
             }
 
+            public bool TryGetValue(string key, out StringValues value)
+            {
+                value = default(StringValues);
+                return false;
+            }
+
             IEnumerator IEnumerable.GetEnumerator()
             {
                 return GetEnumerator();
@@ -132,7 +138,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             IReadOnlyList<IFormFile> IFormFileCollection.GetFiles(string name)
             {
-                throw new NotImplementedException();
+                return null;
             }
         }
     }
diff --git a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/ReadableStringCollectionValueProvider.cs b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormValueProvider.cs
similarity index 86%
rename from src/Microsoft.AspNet.Mvc.Core/ModelBinding/ReadableStringCollectionValueProvider.cs
rename to src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormValueProvider.cs
index fd50bd5be4..c2b13ecf82 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/ReadableStringCollectionValueProvider.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormValueProvider.cs
@@ -9,23 +9,23 @@ using Microsoft.AspNet.Http;
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
     /// <summary>
-    /// An <see cref="IValueProvider"/> adapter for data stored in an <see cref="IReadableStringCollection"/>.
+    /// An <see cref="IValueProvider"/> adapter for data stored in an <see cref="IFormCollection"/>.
     /// </summary>
-    public class ReadableStringCollectionValueProvider : BindingSourceValueProvider, IEnumerableValueProvider
+    public class FormValueProvider : BindingSourceValueProvider, IEnumerableValueProvider
     {
         private readonly CultureInfo _culture;
         private PrefixContainer _prefixContainer;
-        private IReadableStringCollection _values;
+        private IFormCollection _values;
 
         /// <summary>
-        /// Creates a provider for <see cref="IReadableStringCollection"/> wrapping an existing set of key value pairs.
+        /// Creates a value provider for <see cref="IFormCollection"/>.
         /// </summary>
         /// <param name="bindingSource">The <see cref="BindingSource"/> for the data.</param>
         /// <param name="values">The key value pairs to wrap.</param>
         /// <param name="culture">The culture to return with ValueProviderResult instances.</param>
-        public ReadableStringCollectionValueProvider(
+        public FormValueProvider(
             BindingSource bindingSource,
-            IReadableStringCollection values,
+            IFormCollection values,
             CultureInfo culture)
             : base(bindingSource)
         {
diff --git a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormValueProviderFactory.cs b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormValueProviderFactory.cs
index da6e675d50..531b9c5c85 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormValueProviderFactory.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/FormValueProviderFactory.cs
@@ -29,7 +29,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
         private static async Task<IValueProvider> CreateValueProviderAsync(HttpRequest request)
         {
-            return new ReadableStringCollectionValueProvider(
+            return new FormValueProvider(
                 BindingSource.Form,
                 await request.ReadFormAsync(),
                 CultureInfo.CurrentCulture);
diff --git a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/QueryStringValueProvider.cs b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/QueryStringValueProvider.cs
new file mode 100644
index 0000000000..4004985573
--- /dev/null
+++ b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/QueryStringValueProvider.cs
@@ -0,0 +1,103 @@
+// 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 System;
+using System.Collections.Generic;
+using System.Globalization;
+using Microsoft.AspNet.Http;
+
+namespace Microsoft.AspNet.Mvc.ModelBinding
+{
+    /// <summary>
+    /// An <see cref="IValueProvider"/> adapter for data stored in an <see cref="IQueryCollection"/>.
+    /// </summary>
+    public class QueryStringValueProvider : BindingSourceValueProvider, IEnumerableValueProvider
+    {
+        private readonly CultureInfo _culture;
+        private PrefixContainer _prefixContainer;
+        private IQueryCollection _values;
+
+        /// <summary>
+        /// Creates a value provider for <see cref="IQueryCollection"/>.
+        /// </summary>
+        /// <param name="bindingSource">The <see cref="BindingSource"/> for the data.</param>
+        /// <param name="values">The key value pairs to wrap.</param>
+        /// <param name="culture">The culture to return with ValueProviderResult instances.</param>
+        public QueryStringValueProvider(
+            BindingSource bindingSource,
+            IQueryCollection values,
+            CultureInfo culture)
+            : base(bindingSource)
+        {
+            if (bindingSource == null)
+            {
+                throw new ArgumentNullException(nameof(bindingSource));
+            }
+
+            if (values == null)
+            {
+                throw new ArgumentNullException(nameof(values));
+            }
+
+            _values = values;
+            _culture = culture;
+        }
+
+        public CultureInfo Culture
+        {
+            get
+            {
+                return _culture;
+            }
+        }
+
+        protected PrefixContainer PrefixContainer
+        {
+            get
+            {
+                if (_prefixContainer == null)
+                {
+                    _prefixContainer = new PrefixContainer(_values.Keys);
+                }
+
+                return _prefixContainer;
+            }
+        }
+
+        /// <inheritdoc />
+        public override bool ContainsPrefix(string prefix)
+        {
+            return PrefixContainer.ContainsPrefix(prefix);
+        }
+
+        /// <inheritdoc />
+        public virtual IDictionary<string, string> GetKeysFromPrefix(string prefix)
+        {
+            if (prefix == null)
+            {
+                throw new ArgumentNullException(nameof(prefix));
+            }
+
+            return PrefixContainer.GetKeysFromPrefix(prefix);
+        }
+
+        /// <inheritdoc />
+        public override ValueProviderResult GetValue(string key)
+        {
+            if (key == null)
+            {
+                throw new ArgumentNullException(nameof(key));
+            }
+
+            var values = _values[key];
+            if (values.Count == 0)
+            {
+                return ValueProviderResult.None;
+            }
+            else
+            {
+                return new ValueProviderResult(values, _culture);
+            }
+        }
+    }
+}
diff --git a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/QueryStringValueProviderFactory.cs b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/QueryStringValueProviderFactory.cs
index 2e7969b9e9..6538bd0be6 100644
--- a/src/Microsoft.AspNet.Mvc.Core/ModelBinding/QueryStringValueProviderFactory.cs
+++ b/src/Microsoft.AspNet.Mvc.Core/ModelBinding/QueryStringValueProviderFactory.cs
@@ -21,7 +21,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
                 throw new ArgumentNullException(nameof(context));
             }
 
-            return Task.FromResult<IValueProvider>(new ReadableStringCollectionValueProvider(
+            return Task.FromResult<IValueProvider>(new QueryStringValueProvider(
                 BindingSource.Query,
                 context.HttpContext.Request.Query,
                 CultureInfo.InvariantCulture));
diff --git a/src/Microsoft.AspNet.Mvc.TagHelpers/CacheTagHelper.cs b/src/Microsoft.AspNet.Mvc.TagHelpers/CacheTagHelper.cs
index 526b1cb1d1..6a194bc9fe 100644
--- a/src/Microsoft.AspNet.Mvc.TagHelpers/CacheTagHelper.cs
+++ b/src/Microsoft.AspNet.Mvc.TagHelpers/CacheTagHelper.cs
@@ -12,6 +12,7 @@ using Microsoft.AspNet.Mvc.Rendering;
 using Microsoft.AspNet.Mvc.ViewFeatures;
 using Microsoft.AspNet.Razor.TagHelpers;
 using Microsoft.Extensions.Caching.Memory;
+using Microsoft.Extensions.Primitives;
 
 namespace Microsoft.AspNet.Mvc.TagHelpers
 {
@@ -195,9 +196,9 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
                        .Append(VaryBy);
             }
 
-            AddStringCollectionKey(builder, nameof(VaryByCookie), VaryByCookie, request.Cookies);
-            AddStringCollectionKey(builder, nameof(VaryByHeader), VaryByHeader, request.Headers);
-            AddStringCollectionKey(builder, nameof(VaryByQuery), VaryByQuery, request.Query);
+            AddStringCollectionKey(builder, nameof(VaryByCookie), VaryByCookie, request.Cookies, (c, key) => c[key]);
+            AddStringCollectionKey(builder, nameof(VaryByHeader), VaryByHeader, request.Headers, (c, key) => c[key]);
+            AddStringCollectionKey(builder, nameof(VaryByQuery), VaryByQuery, request.Query, (c, key) => c[key]);
             AddVaryByRouteKey(builder);
 
             if (VaryByUser)
@@ -251,7 +252,7 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
             StringBuilder builder,
             string keyName,
             string value,
-            IReadableStringCollection sourceCollection)
+            IDictionary<string, StringValues> sourceCollection)
         {
             if (!string.IsNullOrEmpty(value))
             {
@@ -281,11 +282,12 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
             }
         }
 
-        private static void AddStringCollectionKey(
+        private static void AddStringCollectionKey<T>(
             StringBuilder builder,
             string keyName,
             string value,
-            IHeaderDictionary sourceCollection)
+            T sourceCollection,
+            Func<T, string, StringValues> accessor)
         {
             if (!string.IsNullOrEmpty(value))
             {
@@ -301,7 +303,7 @@ namespace Microsoft.AspNet.Mvc.TagHelpers
 
                     builder.Append(item)
                            .Append(CacheKeyTokenSeparator)
-                           .Append(sourceCollection[item])
+                           .Append(accessor(sourceCollection, item))
                            .Append(CacheKeyTokenSeparator);
                 }
 
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/CompositeValueProviderTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/CompositeValueProviderTest.cs
index 04baa0e398..299bc0cdc0 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/CompositeValueProviderTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/CompositeValueProviderTest.cs
@@ -19,7 +19,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
     {
         protected override IEnumerableValueProvider GetEnumerableValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, StringValues> values,
+            Dictionary<string, StringValues> values,
             CultureInfo culture)
         {
             var emptyValueProvider =
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/DictionaryModelBinderTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/DictionaryModelBinderTest.cs
index b91d45d9b8..9c81b6d3af 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/DictionaryModelBinderTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/DictionaryModelBinderTest.cs
@@ -444,11 +444,12 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var backingStore = dictionary.ToDictionary(
                 kvp => string.Format(keyFormat, kvp.Key),
                 kvp => (StringValues)kvp.Value);
-            var stringCollection = new ReadableStringCollection(backingStore);
+            
+            var formCollection = new FormCollection(backingStore);
 
-            return new ReadableStringCollectionValueProvider(
+            return new FormValueProvider(
                 BindingSource.Form,
-                stringCollection,
+                formCollection,
                 CultureInfo.InvariantCulture);
         }
 
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/EnumerableValueProviderTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/EnumerableValueProviderTest.cs
index d3395fab36..01b0f43664 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/EnumerableValueProviderTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/EnumerableValueProviderTest.cs
@@ -12,7 +12,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 {
     public abstract class EnumerableValueProviderTest
     {
-        private static readonly IDictionary<string, StringValues> _backingStore = new Dictionary<string, StringValues>
+        private static readonly Dictionary<string, StringValues> _backingStore = new Dictionary<string, StringValues>
         {
             { "some", new[] { "someValue1", "someValue2" } },
             { "null_value", StringValues.Empty },
@@ -279,7 +279,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
         private IBindingSourceValueProvider GetBindingSourceValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, StringValues> values,
+            Dictionary<string, StringValues> values,
             CultureInfo culture)
         {
             var provider = GetEnumerableValueProvider(bindingSource, values, culture) as IBindingSourceValueProvider;
@@ -292,7 +292,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
         protected abstract IEnumerableValueProvider GetEnumerableValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, StringValues> values,
+            Dictionary<string, StringValues> values,
             CultureInfo culture);
     }
 }
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormCollectionModelBinderTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormCollectionModelBinderTest.cs
index 4bf57d7979..56adc1032d 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormCollectionModelBinderTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormCollectionModelBinderTest.cs
@@ -134,20 +134,6 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 
             return bindingContext;
         }
-
-        private class MyFormCollection : ReadableStringCollection, IFormCollection
-        {
-            public MyFormCollection(IDictionary<string, StringValues> store) : this(store, new FormFileCollection())
-            {
-            }
-
-            public MyFormCollection(IDictionary<string, StringValues> store, IFormFileCollection files) : base(store)
-            {
-                Files = files;
-            }
-
-            public IFormFileCollection Files { get; private set; }
-        }
     }
 }
 
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormValueProviderFactoryTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormValueProviderFactoryTest.cs
index e6c8c36782..355957f7c4 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormValueProviderFactoryTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormValueProviderFactoryTest.cs
@@ -42,7 +42,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var result = await factory.GetValueProviderAsync(context);
 
             // Assert
-            var valueProvider = Assert.IsType<ReadableStringCollectionValueProvider>(result);
+            var valueProvider = Assert.IsType<FormValueProvider>(result);
             Assert.Equal(CultureInfo.CurrentCulture, valueProvider.Culture);
         }
 
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/ReadableStringCollectionValueProviderTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormValueProviderTest.cs
similarity index 63%
rename from test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/ReadableStringCollectionValueProviderTest.cs
rename to test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormValueProviderTest.cs
index 6e24bbce28..bbbf144f67 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/ReadableStringCollectionValueProviderTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/FormValueProviderTest.cs
@@ -8,15 +8,15 @@ using Microsoft.Extensions.Primitives;
 
 namespace Microsoft.AspNet.Mvc.ModelBinding
 {
-    public class ReadableStringCollectionValueProviderTest : EnumerableValueProviderTest
+    public class FormValueProviderTest : EnumerableValueProviderTest
     {
         protected override IEnumerableValueProvider GetEnumerableValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, StringValues> values,
+            Dictionary<string, StringValues> values,
             CultureInfo culture)
         {
-            var backingStore = new ReadableStringCollection(values);
-            return new ReadableStringCollectionValueProvider(bindingSource, backingStore, culture);
+            var backingStore = new FormCollection(values);
+            return new FormValueProvider(bindingSource, backingStore, culture);
         }
     }
 }
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderFactoryTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderFactoryTest.cs
index 009d54c431..838eca60e8 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderFactoryTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderFactoryTest.cs
@@ -13,7 +13,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
 {
     public class JQueryFormValueProviderFactoryTest
     {
-        private static readonly IDictionary<string, StringValues> _backingStore = new Dictionary<string, StringValues>
+        private static readonly Dictionary<string, StringValues> _backingStore = new Dictionary<string, StringValues>
         {
             { "[]", new[] { "found" } },
             { "[]property1", new[] { "found" } },
@@ -116,7 +116,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
 
         private static ValueProviderFactoryContext CreateContext(
             string contentType,
-            IDictionary<string, StringValues> formValues)
+            Dictionary<string, StringValues> formValues)
         {
             var context = new DefaultHttpContext();
             context.Request.ContentType = contentType;
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderTest.cs
index 18643b1ed2..162cdbdc05 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/JQueryFormValueProviderTest.cs
@@ -11,7 +11,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
     {
         protected override IEnumerableValueProvider GetEnumerableValueProvider(
             BindingSource bindingSource,
-            IDictionary<string, StringValues> values,
+            Dictionary<string, StringValues> values,
             CultureInfo culture)
         {
             return new JQueryFormValueProvider(bindingSource, values, culture);
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/QueryStringValueProviderFactoryTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/QueryStringValueProviderFactoryTest.cs
index ecf753cb1d..1aeb3871bf 100644
--- a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/QueryStringValueProviderFactoryTest.cs
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/QueryStringValueProviderFactoryTest.cs
@@ -23,7 +23,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
         {
             // Arrange
             var request = new Mock<HttpRequest>();
-            request.SetupGet(f => f.Query).Returns(Mock.Of<IReadableStringCollection>());
+            request.SetupGet(f => f.Query).Returns(Mock.Of<IQueryCollection>());
             var context = new Mock<HttpContext>();
             context.SetupGet(c => c.Items).Returns(new Dictionary<object, object>());
             context.SetupGet(c => c.Request).Returns(request.Object);
@@ -35,7 +35,7 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Test
             var result = await _factory.GetValueProviderAsync(factoryContext);
 
             // Assert
-            var valueProvider = Assert.IsType<ReadableStringCollectionValueProvider>(result);
+            var valueProvider = Assert.IsType<QueryStringValueProvider>(result);
             Assert.Equal(CultureInfo.InvariantCulture, valueProvider.Culture);
         }
 #endif
diff --git a/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/QueryStringValueProviderTest.cs b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/QueryStringValueProviderTest.cs
new file mode 100644
index 0000000000..deeb2e9aa9
--- /dev/null
+++ b/test/Microsoft.AspNet.Mvc.Core.Test/ModelBinding/QueryStringValueProviderTest.cs
@@ -0,0 +1,22 @@
+// 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 System.Collections.Generic;
+using System.Globalization;
+using Microsoft.AspNet.Http.Internal;
+using Microsoft.Extensions.Primitives;
+
+namespace Microsoft.AspNet.Mvc.ModelBinding
+{
+    public class QueryStringValueProviderTest : EnumerableValueProviderTest
+    {
+        protected override IEnumerableValueProvider GetEnumerableValueProvider(
+            BindingSource bindingSource,
+            Dictionary<string, StringValues> values,
+            CultureInfo culture)
+        {
+            var backingStore = new QueryCollection(values);
+            return new QueryStringValueProvider(bindingSource, backingStore, culture);
+        }
+    }
+}
diff --git a/test/Microsoft.AspNet.Mvc.IntegrationTests/CollectionModelBinderIntegrationTest.cs b/test/Microsoft.AspNet.Mvc.IntegrationTests/CollectionModelBinderIntegrationTest.cs
index f2be9470ee..c2d13a5a8b 100644
--- a/test/Microsoft.AspNet.Mvc.IntegrationTests/CollectionModelBinderIntegrationTest.cs
+++ b/test/Microsoft.AspNet.Mvc.IntegrationTests/CollectionModelBinderIntegrationTest.cs
@@ -908,7 +908,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
         [MemberData(nameof(CollectionTypeData))]
         public async Task CollectionModelBinder_BindsParameterToExpectedType(
             Type parameterType,
-            IDictionary<string, StringValues> formContent,
+            Dictionary<string, StringValues> formContent,
             Type expectedType)
         {
             // Arrange
diff --git a/test/Microsoft.AspNet.Mvc.IntegrationTests/SimpleTypeModelBinderIntegrationTest.cs b/test/Microsoft.AspNet.Mvc.IntegrationTests/SimpleTypeModelBinderIntegrationTest.cs
index a61b67d16f..ac2d8055ec 100644
--- a/test/Microsoft.AspNet.Mvc.IntegrationTests/SimpleTypeModelBinderIntegrationTest.cs
+++ b/test/Microsoft.AspNet.Mvc.IntegrationTests/SimpleTypeModelBinderIntegrationTest.cs
@@ -438,7 +438,7 @@ namespace Microsoft.AspNet.Mvc.IntegrationTests
 
         [Theory]
         [MemberData(nameof(PersonStoreData))]
-        public async Task BindParameter_FromFormData_BindsCorrectly(IDictionary<string, StringValues> personStore)
+        public async Task BindParameter_FromFormData_BindsCorrectly(Dictionary<string, StringValues> personStore)
         {
             // Arrange
             var argumentBinder = ModelBindingTestHelper.GetArgumentBinder();