diff --git a/Blazor.sln b/Blazor.sln
index 78879d8188..a11eb88570 100644
--- a/Blazor.sln
+++ b/Blazor.sln
@@ -115,7 +115,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BlazorServerSide-CSharp.App
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BlazorServerSide-CSharp.Server", "src\Microsoft.AspNetCore.Blazor.Templates\content\BlazorServerSide-CSharp\BlazorServerSide-CSharp.Server\BlazorServerSide-CSharp.Server.csproj", "{72004416-E278-4787-B84F-40C7E5668D74}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.AspNetCore.Blazor.E2EPerformance", "benchmarks\Microsoft.AspNetCore.Blazor.E2EPerformance\Microsoft.AspNetCore.Blazor.E2EPerformance.csproj", "{CCEC81C4-1A3C-40DC-952F-074712C46180}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Blazor.E2EPerformance", "benchmarks\Microsoft.AspNetCore.Blazor.E2EPerformance\Microsoft.AspNetCore.Blazor.E2EPerformance.csproj", "{CCEC81C4-1A3C-40DC-952F-074712C46180}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Microsoft.AspNetCore.Blazor.TagHelperWorkaround", "src\Microsoft.AspNetCore.Blazor.TagHelperWorkaround\Microsoft.AspNetCore.Blazor.TagHelperWorkaround.csproj", "{F71D78AB-A07E-415D-BF3F-1B9991628214}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -432,6 +434,14 @@ Global
 		{CCEC81C4-1A3C-40DC-952F-074712C46180}.Release|Any CPU.Build.0 = Release|Any CPU
 		{CCEC81C4-1A3C-40DC-952F-074712C46180}.ReleaseNoVSIX|Any CPU.ActiveCfg = Release|Any CPU
 		{CCEC81C4-1A3C-40DC-952F-074712C46180}.ReleaseNoVSIX|Any CPU.Build.0 = Release|Any CPU
+		{F71D78AB-A07E-415D-BF3F-1B9991628214}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{F71D78AB-A07E-415D-BF3F-1B9991628214}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{F71D78AB-A07E-415D-BF3F-1B9991628214}.DebugNoVSIX|Any CPU.ActiveCfg = Debug|Any CPU
+		{F71D78AB-A07E-415D-BF3F-1B9991628214}.DebugNoVSIX|Any CPU.Build.0 = Debug|Any CPU
+		{F71D78AB-A07E-415D-BF3F-1B9991628214}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{F71D78AB-A07E-415D-BF3F-1B9991628214}.Release|Any CPU.Build.0 = Release|Any CPU
+		{F71D78AB-A07E-415D-BF3F-1B9991628214}.ReleaseNoVSIX|Any CPU.ActiveCfg = Release|Any CPU
+		{F71D78AB-A07E-415D-BF3F-1B9991628214}.ReleaseNoVSIX|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -485,6 +495,7 @@ Global
 		{49F0DC0E-D8E6-4E74-8A3F-F024EAAECB8B} = {6BDD3018-3961-488E-97D3-1FB7320A8AC6}
 		{72004416-E278-4787-B84F-40C7E5668D74} = {6BDD3018-3961-488E-97D3-1FB7320A8AC6}
 		{CCEC81C4-1A3C-40DC-952F-074712C46180} = {36A7DEB7-5F88-4BFB-B57E-79EEC9950E25}
+		{F71D78AB-A07E-415D-BF3F-1B9991628214} = {B867E038-B3CE-43E3-9292-61568C46CDEB}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {504DA352-6788-4DC0-8705-82167E72A4D3}
diff --git a/build/SignToolData.json b/build/SignToolData.json
index 16d7616b5b..8c629bae65 100644
--- a/build/SignToolData.json
+++ b/build/SignToolData.json
@@ -7,6 +7,7 @@
         "bin/Microsoft.AspNetCore.Blazor.Browser.JS/netcoreapp2.1/Microsoft.AspNetCore.Blazor.Browser.JS.dll",
         "bin/Microsoft.AspNetCore.Blazor.Browser/netstandard2.0/Microsoft.AspNetCore.Blazor.Browser.dll",
         "bin/Microsoft.AspNetCore.Blazor.Server/netstandard2.0/Microsoft.AspNetCore.Blazor.Server.dll",
+        "bin/Microsoft.AspNetCore.Blazor.TagHelperWorkaround/netstandard1.0/Microsoft.AspNetCore.Blazor.TagHelperWorkaround.dll",
         "bin/Microsoft.AspNetCore.Blazor.Build/netcoreapp2.1/Microsoft.AspNetCore.Blazor.Build.dll",
         "bin/Microsoft.AspNetCore.Blazor.Cli/netcoreapp2.1/dotnet-blazor.dll",
         "bin/Microsoft.AspNetCore.Blazor.Razor.Extensions/net461/Microsoft.AspNetCore.Blazor.Razor.Extensions.dll",
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.csproj b/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.csproj
index 1896761f8a..53cf4d6f60 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.csproj
+++ b/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.csproj
@@ -41,6 +41,7 @@
     <ProjectReference Include="..\Microsoft.AspNetCore.Blazor.Browser.JS\Microsoft.AspNetCore.Blazor.Browser.JS.csproj" />
     <ProjectReference Include="..\Microsoft.AspNetCore.Blazor.Razor.Extensions\Microsoft.AspNetCore.Blazor.Razor.Extensions.csproj" />
     <ProjectReference Include="..\Microsoft.AspNetCore.Blazor\Microsoft.AspNetCore.Blazor.csproj" />
+    <ProjectReference Include="..\Microsoft.AspNetCore.Blazor.TagHelperWorkaround\Microsoft.AspNetCore.Blazor.TagHelperWorkaround.csproj" />
 
     <!-- Intentionally include Razor.Design's MSBuild assets for everyone who reference Blazor.Build -->
     <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="$(RazorPackageVersion)" PrivateAssets="None" />
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.nuspec b/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.nuspec
index bbac5b9b57..58d7842eae 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.nuspec
+++ b/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.nuspec
@@ -11,10 +11,10 @@
     </dependencies>
   </metadata>
   <files>
-    <file src="_._" target="lib/netstandard1.0/" />
+    <file src="$publishdir$netcoreapp2.1\Microsoft.AspNetCore.Blazor.TagHelperWorkaround.dll" target="lib/netstandard1.0/" />
     <file src="build\**" target="build" />
     <file src="targets\**" target="targets" />
-    <file src="$publishdir$\netcoreapp2.1\**\*" target="tools/" />
+    <file src="$publishdir$netcoreapp2.1\**\*" target="tools/" />
     <file src="..\mono\dist\optimized\**\*" target="tools\mono"  />
     <file src="..\mono\tools\binaries\illink\**\*.*" target="tools\illink" />
     <file src="..\Microsoft.AspNetCore.Blazor.Browser.JS\dist\blazor.*.js" target="tools\blazor" />
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/ReferenceFromSource.props b/src/Microsoft.AspNetCore.Blazor.Build/ReferenceFromSource.props
index b0a6cdcf57..ef30bab8fc 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/ReferenceFromSource.props
+++ b/src/Microsoft.AspNetCore.Blazor.Build/ReferenceFromSource.props
@@ -29,6 +29,11 @@
     <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="$(RazorPackageVersion)"/>
   </ItemGroup>
 
+  <!-- This is used as a P2P when building the repo. Normal Blazor projects will get this as a reference through the Blazor.Build package -->
+  <ItemGroup>
+    <ProjectReference Include="$(MSBuildThisFileDirectory)..\Microsoft.AspNetCore.Blazor.TagHelperWorkaround\Microsoft.AspNetCore.Blazor.TagHelperWorkaround.csproj" PrivateAssets="all" />
+  </ItemGroup>
+
   <Target
     Name="BuildBlazorBuildBinary"
     BeforeTargets="BlazorGenerateDeclaration">
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/_._ b/src/Microsoft.AspNetCore.Blazor.Build/_._
deleted file mode 100644
index 5f282702bb..0000000000
--- a/src/Microsoft.AspNetCore.Blazor.Build/_._
+++ /dev/null
@@ -1 +0,0 @@
-
\ No newline at end of file
diff --git a/src/Microsoft.AspNetCore.Blazor/ITagHelper.cs b/src/Microsoft.AspNetCore.Blazor.TagHelperWorkaround/ITagHelper.cs
similarity index 68%
rename from src/Microsoft.AspNetCore.Blazor/ITagHelper.cs
rename to src/Microsoft.AspNetCore.Blazor.TagHelperWorkaround/ITagHelper.cs
index 28409cdf3b..1bc3eb200a 100644
--- a/src/Microsoft.AspNetCore.Blazor/ITagHelper.cs
+++ b/src/Microsoft.AspNetCore.Blazor.TagHelperWorkaround/ITagHelper.cs
@@ -10,6 +10,10 @@ namespace Microsoft.AspNetCore.Razor.TagHelpers
     // This is an unfortunate workaround due to https://github.com/aspnet/Razor/issues/2482
     // The Razor tooling looks for a type with exactly this name and will prevent tag helper
     // discovery if it is not found.
+    //
+    // This has to be its own assembly because we need to reference it in Blazor component libraries
+    // in order for component discovery to work, but if we allow it as a reference for server-side
+    // projects it will break MVC's features.
     internal class ITagHelper
     {
     }
diff --git a/src/Microsoft.AspNetCore.Blazor.TagHelperWorkaround/Microsoft.AspNetCore.Blazor.TagHelperWorkaround.csproj b/src/Microsoft.AspNetCore.Blazor.TagHelperWorkaround/Microsoft.AspNetCore.Blazor.TagHelperWorkaround.csproj
new file mode 100644
index 0000000000..762ab88bd2
--- /dev/null
+++ b/src/Microsoft.AspNetCore.Blazor.TagHelperWorkaround/Microsoft.AspNetCore.Blazor.TagHelperWorkaround.csproj
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <!-- This assembly ships in Blazor.Build -->
+  <PropertyGroup>
+    <TargetFramework>netstandard1.0</TargetFramework>
+    <IsPackable>false</IsPackable> 
+  </PropertyGroup>
+
+</Project>