diff --git a/src/Microsoft.AspNetCore.Mvc.Razor.Host/MvcRazorParser.cs b/src/Microsoft.AspNetCore.Mvc.Razor.Host/MvcRazorParser.cs
index 086f4ba2c1..ba7eb42e64 100644
--- a/src/Microsoft.AspNetCore.Mvc.Razor.Host/MvcRazorParser.cs
+++ b/src/Microsoft.AspNetCore.Mvc.Razor.Host/MvcRazorParser.cs
@@ -87,29 +87,7 @@ protected override IEnumerable<TagHelperDescriptor> GetTagHelperDescriptors(
                 _viewImportsDirectiveDescriptors,
                 errorSink);
 
-            var descriptors = visitor.GetDescriptors(documentRoot);
-            foreach (var descriptor in descriptors)
-            {
-                foreach (var attributeDescriptor in descriptor.Attributes)
-                {
-                    if (attributeDescriptor.IsIndexer &&
-                        string.Equals(
-                            attributeDescriptor.TypeName,
-                            _modelExpressionTypeName,
-                            StringComparison.Ordinal))
-                    {
-                        errorSink.OnError(
-                            SourceLocation.Undefined,
-                            Resources.FormatMvcRazorParser_InvalidPropertyType(
-                                descriptor.TypeName,
-                                attributeDescriptor.Name,
-                                _modelExpressionTypeName),
-                            length: 0);
-                    }
-                }
-            }
-
-            return descriptors;
+            return visitor.GetDescriptors(documentRoot);
         }
 
         private static IEnumerable<TagHelperDirectiveDescriptor> GetTagHelperDirectiveDescriptors(
diff --git a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/TagHelpersWebSite.Home.Index.html b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/TagHelpersWebSite.Home.Index.html
index dcf5fd12da..27bc4cf95a 100644
--- a/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/TagHelpersWebSite.Home.Index.html
+++ b/test/Microsoft.AspNetCore.Mvc.FunctionalTests/compiler/resources/TagHelpersWebSite.Home.Index.html
@@ -39,6 +39,11 @@ <h3 style="font-family: cursive;">Current Tag Cloud from ViewComponentHelper:</h
 <br /><p><em>Rendering Template:</em></p>
 <div><h3 style="font-family: cursive;">Tag Cloud from Template: </h3>Lorem,ipsum,dolor,sit,amet,consectetur,adipisicing,elit,sed,do,eiusmod,tempor,incididunt,ut,labore,et,dolore,magna,aliquaUt,enim</div></div>
 
+<div>
+    <h3 style="font-family: cursive;">Dictionary Valued Model Expression</h3>
+    <div><ul><li>TagsToShow</li><li>Version.Build</li></ul></div>
+</div>
+
 
         <hr />
         <footer>
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/DictionaryPrefixTestTagHelper.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/DictionaryPrefixTestTagHelper.cs
new file mode 100644
index 0000000000..15e7cf721a
--- /dev/null
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/DictionaryPrefixTestTagHelper.cs
@@ -0,0 +1,17 @@
+using Microsoft.AspNetCore.Mvc.ViewFeatures;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+using System.Collections.Generic;
+
+namespace Microsoft.AspNetCore.Mvc.Razor.Host.Test
+{
+    [HtmlTargetElement(Attributes = "prefix-*")]
+    public class DictionaryPrefixTestTagHelper : TagHelper
+    {
+        [HtmlAttributeName(DictionaryAttributePrefix = "prefix-")]
+        public IDictionary<string, ModelExpression> PrefixValues { get; set; } = new Dictionary<string, ModelExpression>();
+
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+        }
+    }
+}
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/Internal/ViewComponentTagHelperChunkVisitorTest.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/Internal/ViewComponentTagHelperChunkVisitorTest.cs
index b3dc7fb59c..49e772837f 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/Internal/ViewComponentTagHelperChunkVisitorTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/Internal/ViewComponentTagHelperChunkVisitorTest.cs
@@ -7,6 +7,7 @@
 using Microsoft.AspNetCore.Razor.Chunks;
 using Microsoft.AspNetCore.Razor.CodeGenerators;
 using Xunit;
+using System;
 
 namespace Microsoft.AspNetCore.Mvc.Razor.Host.Test.Internal
 {
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/MvcRazorHostTest.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/MvcRazorHostTest.cs
index 74402918dd..57218deb8d 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/MvcRazorHostTest.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/MvcRazorHostTest.cs
@@ -142,32 +142,49 @@ public void MvcRazorHost_GeneratesTagHelperModelExpressionCode_DesignTime()
                     generatedLineIndex: 17,
                     generatedCharacterIndex: 48,
                     contentLength: 91),
+                BuildLineMapping(
+                    documentAbsoluteIndex: 140,
+                    documentLineIndex: 3,
+                    documentCharacterIndex: 14,
+                    generatedAbsoluteIndex: 797,
+                    generatedLineIndex: 18,
+                    generatedCharacterIndex: 48,
+                    contentLength: 102),
                 BuildLineMapping(
                     documentAbsoluteIndex: 7,
                     documentLineIndex: 0,
                     documentCharacterIndex: 7,
-                    generatedAbsoluteIndex: 836,
-                    generatedLineIndex: 19,
+                    generatedAbsoluteIndex: 990,
+                    generatedLineIndex: 20,
                     generatedCharacterIndex: 28,
                     contentLength: 8),
                 BuildLineMapping(
-                    documentAbsoluteIndex: 145,
-                    documentLineIndex: 4,
+                    documentAbsoluteIndex: 263,
+                    documentLineIndex: 5,
                     documentCharacterIndex: 17,
-                    generatedAbsoluteIndex: 2530,
-                    generatedLineIndex: 50,
+                    generatedAbsoluteIndex: 2684,
+                    generatedLineIndex: 51,
                     generatedCharacterIndex: 133,
                     contentLength: 3),
                 BuildLineMapping(
-                    documentAbsoluteIndex: 172,
-                    documentLineIndex: 5,
+                    documentAbsoluteIndex: 290,
+                    documentLineIndex: 6,
                     documentCharacterIndex: 18,
-                    generatedAbsoluteIndex: 2897,
-                    generatedLineIndex: 56,
+                    generatedAbsoluteIndex: 3051,
+                    generatedLineIndex: 57,
                     generatedCharacterIndex: 125,
                     contentLength: 5),
+                BuildLineMapping(
+                    documentAbsoluteIndex: 322,
+                    documentLineIndex: 8,
+                    documentCharacterIndex: 19,
+                    generatedAbsoluteIndex: 3169,
+                    generatedLineIndex: 62,
+                    generatedCharacterIndex: 19,
+                    contentLength: 5),
             };
 
+
             // Act and Assert
             RunDesignTimeTest(
                 host,
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Input/ModelExpressionTagHelper.cshtml b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Input/ModelExpressionTagHelper.cshtml
index fc408467f0..d788b65475 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Input/ModelExpressionTagHelper.cshtml
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Input/ModelExpressionTagHelper.cshtml
@@ -1,6 +1,9 @@
 @model DateTime
 
 @addTagHelper Microsoft.AspNetCore.Mvc.Razor.InputTestTagHelper, Microsoft.AspNetCore.Mvc.Razor.Host.Test
+@addTagHelper Microsoft.AspNetCore.Mvc.Razor.DictionaryPrefixTestTagHelper, Microsoft.AspNetCore.Mvc.Razor.Host.Test
 
 <input-test for="Now" />
-<input-test for="@Model" />
\ No newline at end of file
+<input-test for="@Model" />
+
+<div prefix-test="@Model" ></div>
\ No newline at end of file
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.cs
index 47be6e965e..09e12cba97 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Output/DesignTime/ModelExpressionTagHelper.cs
@@ -16,6 +16,7 @@ private void @__RazorDesignTimeHelpers__()
             #pragma warning disable 219
             string __tagHelperDirectiveSyntaxHelper = null;
             __tagHelperDirectiveSyntaxHelper = "Microsoft.AspNetCore.Mvc.Razor.InputTestTagHelper, Microsoft.AspNetCore.Mvc.Razor.Host.Test";
+            __tagHelperDirectiveSyntaxHelper = "Microsoft.AspNetCore.Mvc.Razor.DictionaryPrefixTestTagHelper, Microsoft.AspNetCore.Mvc.Razor.Host.Test";
 #line 1 "testfiles/input/modelexpressiontaghelper.cshtml"
 var __modelHelper = default(DateTime);
 
@@ -47,15 +48,20 @@ public testfiles_input_modelexpressiontaghelper_cshtml()
         public override async Task ExecuteAsync()
         {
             __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper = CreateTagHelper<global::Microsoft.AspNetCore.Mvc.Razor.InputTestTagHelper>();
-#line 5 "testfiles/input/modelexpressiontaghelper.cshtml"
+#line 6 "testfiles/input/modelexpressiontaghelper.cshtml"
 __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper.For = ModelExpressionProvider.CreateModelExpression(ViewData, __model => __model.Now);
 
 #line default
 #line hidden
             __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper = CreateTagHelper<global::Microsoft.AspNetCore.Mvc.Razor.InputTestTagHelper>();
-#line 6 "testfiles/input/modelexpressiontaghelper.cshtml"
+#line 7 "testfiles/input/modelexpressiontaghelper.cshtml"
 __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper.For = ModelExpressionProvider.CreateModelExpression(ViewData, __model => Model);
 
+#line default
+#line hidden
+#line 9 "testfiles/input/modelexpressiontaghelper.cshtml"
+             __o = Model;
+
 #line default
 #line hidden
         }
diff --git a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Output/Runtime/ModelExpressionTagHelper.cs b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Output/Runtime/ModelExpressionTagHelper.cs
index 30e09a89bd..f51d26f0e1 100644
--- a/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Output/Runtime/ModelExpressionTagHelper.cs
+++ b/test/Microsoft.AspNetCore.Mvc.Razor.Host.Test/TestFiles/Output/Runtime/ModelExpressionTagHelper.cs
@@ -1,4 +1,4 @@
-#pragma checksum "TestFiles/Input/ModelExpressionTagHelper.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "bb128a8b2ca348e77a9b5481e541b5a8bf82de0b"
+#pragma checksum "TestFiles/Input/ModelExpressionTagHelper.cshtml" "{ff1816ec-aa5e-4d10-87f7-6f4963833460}" "9e4cf6e4030f5e9e62458b1f7608e7a70cfaa4e0"
 namespace AspNetCore
 {
     using System;
@@ -42,7 +42,7 @@ public override async Task ExecuteAsync()
         {
             __tagHelperRunner = __tagHelperRunner ?? new global::Microsoft.AspNetCore.Razor.Runtime.TagHelpers.TagHelperRunner();
             __tagHelperScopeManager = __tagHelperScopeManager ?? new global::Microsoft.AspNetCore.Razor.Runtime.TagHelpers.TagHelperScopeManager(StartTagHelperWritingScope, EndTagHelperWritingScope);
-            BeginContext(126, 2, true);
+            BeginContext(244, 2, true);
             WriteLiteral("\r\n");
             EndContext();
             __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input-test", global::Microsoft.AspNetCore.Razor.TagHelpers.TagMode.SelfClosing, "test", async() => {
@@ -50,18 +50,18 @@ public override async Task ExecuteAsync()
             );
             __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper = CreateTagHelper<global::Microsoft.AspNetCore.Mvc.Razor.InputTestTagHelper>();
             __tagHelperExecutionContext.Add(__Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper);
-#line 5 "TestFiles/Input/ModelExpressionTagHelper.cshtml"
+#line 6 "TestFiles/Input/ModelExpressionTagHelper.cshtml"
 __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper.For = ModelExpressionProvider.CreateModelExpression(ViewData, __model => __model.Now);
 
 #line default
 #line hidden
             __tagHelperExecutionContext.AddTagHelperAttribute("for", __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper.For, global::Microsoft.AspNetCore.Razor.TagHelpers.HtmlAttributeValueStyle.DoubleQuotes);
             await __tagHelperRunner.RunAsync(__tagHelperExecutionContext);
-            BeginContext(128, 24, false);
+            BeginContext(246, 24, false);
             Write(__tagHelperExecutionContext.Output);
             EndContext();
             __tagHelperExecutionContext = __tagHelperScopeManager.End();
-            BeginContext(152, 2, true);
+            BeginContext(270, 2, true);
             WriteLiteral("\r\n");
             EndContext();
             __tagHelperExecutionContext = __tagHelperScopeManager.Begin("input-test", global::Microsoft.AspNetCore.Razor.TagHelpers.TagMode.SelfClosing, "test", async() => {
@@ -69,17 +69,30 @@ public override async Task ExecuteAsync()
             );
             __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper = CreateTagHelper<global::Microsoft.AspNetCore.Mvc.Razor.InputTestTagHelper>();
             __tagHelperExecutionContext.Add(__Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper);
-#line 6 "TestFiles/Input/ModelExpressionTagHelper.cshtml"
+#line 7 "TestFiles/Input/ModelExpressionTagHelper.cshtml"
 __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper.For = ModelExpressionProvider.CreateModelExpression(ViewData, __model => Model);
 
 #line default
 #line hidden
             __tagHelperExecutionContext.AddTagHelperAttribute("for", __Microsoft_AspNetCore_Mvc_Razor_InputTestTagHelper.For, global::Microsoft.AspNetCore.Razor.TagHelpers.HtmlAttributeValueStyle.DoubleQuotes);
             await __tagHelperRunner.RunAsync(__tagHelperExecutionContext);
-            BeginContext(154, 27, false);
+            BeginContext(272, 27, false);
             Write(__tagHelperExecutionContext.Output);
             EndContext();
             __tagHelperExecutionContext = __tagHelperScopeManager.End();
+            BeginContext(299, 8, true);
+            WriteLiteral("\r\n\r\n<div");
+            EndContext();
+            BeginWriteAttribute("prefix-test", " prefix-test=\"", 307, "\"", 327, 1);
+#line 9 "TestFiles/Input/ModelExpressionTagHelper.cshtml"
+WriteAttributeValue("", 321, Model, 321, 6, false);
+
+#line default
+#line hidden
+            EndWriteAttribute();
+            BeginContext(328, 8, true);
+            WriteLiteral(" ></div>");
+            EndContext();
         }
         #pragma warning restore 1998
     }
diff --git a/test/WebSites/TagHelpersWebSite/Startup.cs b/test/WebSites/TagHelpersWebSite/Startup.cs
index 696c61dde0..556c8c6bf4 100644
--- a/test/WebSites/TagHelpersWebSite/Startup.cs
+++ b/test/WebSites/TagHelpersWebSite/Startup.cs
@@ -20,6 +20,8 @@ public void Configure(IApplicationBuilder app)
         {
             app.UseCultureReplacer();
 
+            app.UseDeveloperExceptionPage();
+
             app.UseMvcWithDefaultRoute();
         }
 
diff --git a/test/WebSites/TagHelpersWebSite/TagHelpers/DictionaryPrefixTestTagHelper.cs b/test/WebSites/TagHelpersWebSite/TagHelpers/DictionaryPrefixTestTagHelper.cs
new file mode 100644
index 0000000000..0a820a9080
--- /dev/null
+++ b/test/WebSites/TagHelpersWebSite/TagHelpers/DictionaryPrefixTestTagHelper.cs
@@ -0,0 +1,31 @@
+using Microsoft.AspNetCore.Mvc.ViewFeatures;
+using Microsoft.AspNetCore.Razor.TagHelpers;
+using System.Linq;
+using System.Collections.Generic;
+using Microsoft.AspNetCore.Mvc.Rendering;
+
+namespace Microsoft.AspNetCore.Mvc.Razor.Host.Test
+{
+    [HtmlTargetElement(Attributes = "prefix-*")]
+    public class DictionaryPrefixTestTagHelper : TagHelper
+    {
+        [HtmlAttributeName(DictionaryAttributePrefix = "prefix-")]
+        public IDictionary<string, ModelExpression> PrefixValues { get; set; } = new Dictionary<string, ModelExpression>();
+
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            var ulTag = new TagBuilder("ul");
+
+            foreach (var item in PrefixValues)
+            {
+                var liTag = new TagBuilder("li");
+                
+                liTag.InnerHtml.Append(item.Value.Name);
+
+                ulTag.InnerHtml.AppendHtml(liTag);
+            }
+
+            output.Content.SetHtmlContent(ulTag);
+        }
+    }
+}
diff --git a/test/WebSites/TagHelpersWebSite/Views/Home/Index.cshtml b/test/WebSites/TagHelpersWebSite/Views/Home/Index.cshtml
index ca2c33b94e..2af1cd0a61 100644
--- a/test/WebSites/TagHelpersWebSite/Views/Home/Index.cshtml
+++ b/test/WebSites/TagHelpersWebSite/Views/Home/Index.cshtml
@@ -43,6 +43,11 @@
     }
 </div>
 
+<div>
+    <h3>Dictionary Valued Model Expression</h3>
+    <div prefix-test1="@Model.TagsToShow" prefix-test2="@Model.Version.Build"></div>
+</div>
+
 @section footerContent {
     <p condition="Model.Approved" bold surround="section">&copy; @Model.CopyrightYear - My ASP.NET Application</p>
 }
\ No newline at end of file
diff --git a/test/WebSites/TagHelpersWebSite/project.json b/test/WebSites/TagHelpersWebSite/project.json
index 8211cd4d13..e609bb6bbf 100644
--- a/test/WebSites/TagHelpersWebSite/project.json
+++ b/test/WebSites/TagHelpersWebSite/project.json
@@ -6,6 +6,7 @@
     "preserveCompilationContext": true
   },
   "dependencies": {
+    "Microsoft.AspNetCore.Diagnostics": "1.1.0-alpha1-22244",
     "Microsoft.AspNetCore.Mvc": "1.1.0-*",
     "Microsoft.AspNetCore.Mvc.TestConfiguration": "1.0.0",
     "Microsoft.AspNetCore.Razor.Tools": {
@@ -19,7 +20,7 @@
   "frameworks": {
     "net451": {},
     "netcoreapp1.0": {
-      "dependencies": {
+      "dependencies": {        
         "Microsoft.NETCore.App": {
           "version": "1.0.0-*",
           "type": "platform"