diff --git a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Mono/MonoPlatform.ts b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Mono/MonoPlatform.ts
index 0f1c362c2d..2309fdec01 100644
--- a/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Mono/MonoPlatform.ts
+++ b/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Platform/Mono/MonoPlatform.ts
@@ -175,21 +175,13 @@ function findMethod(assemblyName: string, namespace: string, className: string,
 }
 
 function addScriptTagsToDocument() {
-  // Load either the wasm or asm.js version of the Mono runtime
   const browserSupportsNativeWebAssembly = typeof WebAssembly !== 'undefined' && WebAssembly.validate;
-  const monoRuntimeUrlBase = '_framework/' + (browserSupportsNativeWebAssembly ? 'wasm' : 'asmjs');
-  const monoRuntimeScriptUrl = `${monoRuntimeUrlBase}/mono.js`;
-
   if (!browserSupportsNativeWebAssembly) {
-    // In the asmjs case, the initial memory structure is in a separate file we need to download
-    const meminitXHR = Module['memoryInitializerRequest'] = new XMLHttpRequest();
-    meminitXHR.open('GET', `${monoRuntimeUrlBase}/mono.js.mem`);
-    meminitXHR.responseType = 'arraybuffer';
-    meminitXHR.send(undefined);
+    throw new Error('This browser does not support WebAssembly.');
   }
 
   const scriptElem = document.createElement('script');
-  scriptElem.src = monoRuntimeScriptUrl;
+  scriptElem.src = '_framework/wasm/mono.js';
   scriptElem.defer = true;
   document.body.appendChild(scriptElem);
 }
@@ -197,7 +189,6 @@ function addScriptTagsToDocument() {
 function createEmscriptenModuleInstance(loadAssemblyUrls: string[], onReady: () => void, onError: (reason?: any) => void) {
   const module = {} as typeof Module;
   const wasmBinaryFile = '_framework/wasm/mono.wasm';
-  const asmjsCodeFile = '_framework/asmjs/mono.asm.js';
   const suppressMessages = ['DEBUGGING ENABLED'];
 
   module.print = line => (suppressMessages.indexOf(line) < 0 && console.log(`WASM: ${line}`));
@@ -209,7 +200,6 @@ function createEmscriptenModuleInstance(loadAssemblyUrls: string[], onReady: ()
   module.locateFile = fileName => {
     switch (fileName) {
       case 'mono.wasm': return wasmBinaryFile;
-      case 'mono.asm.js': return asmjsCodeFile;
       default: return fileName;
     }
   };
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.nuspec b/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.nuspec
index 631bd09a80..8814697ce8 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.nuspec
+++ b/src/Microsoft.AspNetCore.Blazor.Build/Microsoft.AspNetCore.Blazor.Build.nuspec
@@ -18,7 +18,7 @@
     <file src="build\**" target="build" />
     <file src="targets\**" target="targets" />
     <file src="$publishdir$netcoreapp2.1\**\*" target="tools/" />
-    <file src="..\mono\dist\optimized\**\*" target="tools\mono"  />
+    <file src="..\mono\dist\**\*" target="tools\mono"  />
     <file src="..\mono\tools\binaries\illink\**\*.*" target="tools\illink" />
     <file src="..\Microsoft.AspNetCore.Blazor.Browser.JS\dist\blazor.*.js" target="tools\blazor" />
   </files>
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/ReferenceFromSource.props b/src/Microsoft.AspNetCore.Blazor.Build/ReferenceFromSource.props
index 64d7bbe5f6..501e48fd40 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/ReferenceFromSource.props
+++ b/src/Microsoft.AspNetCore.Blazor.Build/ReferenceFromSource.props
@@ -12,10 +12,9 @@
     <BlazorBuildReferenceFromSource>true</BlazorBuildReferenceFromSource>
     <BlazorMonoRuntimeBasePath>$(MSBuildThisFileDirectory)../mono/</BlazorMonoRuntimeBasePath>
     <MonoLinkerPath>$(BlazorMonoRuntimeBasePath)tools/binaries/illink/illink.dll</MonoLinkerPath>
-    <MonoBaseClassLibraryPath>$(BlazorMonoRuntimeBasePath)dist/optimized/bcl/</MonoBaseClassLibraryPath>
-    <MonoBaseClassLibraryFacadesPath>$(BlazorMonoRuntimeBasePath)dist/optimized/bcl/Facades/</MonoBaseClassLibraryFacadesPath>
-    <MonoAsmjsRuntimePath>$(BlazorMonoRuntimeBasePath)dist/optimized/asmjs/</MonoAsmjsRuntimePath>
-    <MonoWasmRuntimePath>$(BlazorMonoRuntimeBasePath)dist/optimized/wasm/</MonoWasmRuntimePath>
+    <MonoBaseClassLibraryPath>$(BlazorMonoRuntimeBasePath)dist/bcl/</MonoBaseClassLibraryPath>
+    <MonoBaseClassLibraryFacadesPath>$(BlazorMonoRuntimeBasePath)dist/bcl/Facades/</MonoBaseClassLibraryFacadesPath>
+    <MonoWasmRuntimePath>$(BlazorMonoRuntimeBasePath)dist/wasm/</MonoWasmRuntimePath>
     <BlazorJsPath>$(MSBuildThisFileDirectory)../Microsoft.AspNetCore.Blazor.Browser.JS/dist/blazor.*.js</BlazorJsPath>
   </PropertyGroup>
 
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.props b/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.props
index 54f184f139..0db40a4a5c 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.props
+++ b/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.props
@@ -4,7 +4,6 @@
     <MonoLinkerPath>$(BlazorMonoRuntimeBasePath)tools/illink/illink.dll</MonoLinkerPath>
     <MonoBaseClassLibraryPath>$(BlazorMonoRuntimeBasePath)tools/mono/bcl/</MonoBaseClassLibraryPath>
     <MonoBaseClassLibraryFacadesPath>$(BlazorMonoRuntimeBasePath)tools/mono/bcl/Facades/</MonoBaseClassLibraryFacadesPath>
-    <MonoAsmjsRuntimePath>$(BlazorMonoRuntimeBasePath)tools/mono/asmjs/</MonoAsmjsRuntimePath>
     <MonoWasmRuntimePath>$(BlazorMonoRuntimeBasePath)tools/mono/wasm/</MonoWasmRuntimePath>
     <BlazorJsPath>$(BlazorMonoRuntimeBasePath)tools/blazor/blazor.*.js</BlazorJsPath>
   </PropertyGroup>
@@ -16,7 +15,6 @@
     <BaseBlazorPackageContentOutputPath>$(BaseBlazorDistPath)_content/</BaseBlazorPackageContentOutputPath>
     <BaseBlazorRuntimeOutputPath>$(BaseBlazorDistPath)_framework/</BaseBlazorRuntimeOutputPath>
     <BaseBlazorRuntimeBinOutputPath>$(BaseBlazorRuntimeOutputPath)_bin/</BaseBlazorRuntimeBinOutputPath>
-    <BaseBlazorRuntimeAsmjsOutputPath>$(BaseBlazorRuntimeOutputPath)asmjs/</BaseBlazorRuntimeAsmjsOutputPath>
     <BaseBlazorRuntimeWasmOutputPath>$(BaseBlazorRuntimeOutputPath)wasm/</BaseBlazorRuntimeWasmOutputPath>
     <BaseBlazorJsOutputPath>$(BaseBlazorRuntimeOutputPath)</BaseBlazorJsOutputPath>
     <BaseBlazorIntermediateOutputPath>blazor/</BaseBlazorIntermediateOutputPath>
diff --git a/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.targets b/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.targets
index 440d375ca3..6069af9026 100644
--- a/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.targets
+++ b/src/Microsoft.AspNetCore.Blazor.Build/targets/Blazor.MonoRuntime.targets
@@ -122,7 +122,6 @@
 
     The final folder is something like bin/<<Configuration>>/<<TargetFramework>>/dist
     /_framework/_bin <- This will contain either the BCL + app assemblies or the result of linking the app.
-    /_framework/asmjs <- This will contain the asmjs runtime copied from the nuget package.
     /_framework/wasm <- This will contain the wsm runtime copied from the nuget package.
     /_framework/blazor.js <- This is the blazor.js file copied from the nuget package.
     /_framework/blazor.boot.json <- This is the boot json file
@@ -157,14 +156,8 @@
     </PropertyGroup>
 
     <ItemGroup Label="Static content to copy to the output folder">
-      <MonoAsmjsFile Include="$(MonoAsmjsRuntimePath)**/*.*" />
       <MonoWasmFile Include="$(MonoWasmRuntimePath)**/*.*" />
       <BlazorJsFile Include="$(BlazorJsPath)" />
-      <BlazorItemOutput Include="@(MonoAsmjsFile)">
-        <TargetOutputPath>$(TargetDir)$(BaseBlazorRuntimeAsmjsOutputPath)%(FileName)%(Extension)</TargetOutputPath>
-        <Type>AsmJs</Type>
-        <IsStatic>true</IsStatic>
-      </BlazorItemOutput>
       <BlazorItemOutput Include="@(MonoWasmFile)">
         <TargetOutputPath>$(TargetDir)$(BaseBlazorRuntimeWasmOutputPath)%(FileName)%(Extension)</TargetOutputPath>
         <Type>WebAssembly</Type>
diff --git a/test/Microsoft.AspNetCore.Blazor.Build.Test/RuntimeDependenciesResolverTest.cs b/test/Microsoft.AspNetCore.Blazor.Build.Test/RuntimeDependenciesResolverTest.cs
index 3652a45eb8..37186c963d 100644
--- a/test/Microsoft.AspNetCore.Blazor.Build.Test/RuntimeDependenciesResolverTest.cs
+++ b/test/Microsoft.AspNetCore.Blazor.Build.Test/RuntimeDependenciesResolverTest.cs
@@ -35,8 +35,8 @@ namespace Microsoft.AspNetCore.Blazor.Build.Test
             var basePath = Path.GetDirectoryName(typeof(RuntimeDependenciesResolverTest).Assembly.Location);
             var bclLocations = new []
             {
-                Path.Combine(basePath, "../../../../../src/mono/dist/optimized/bcl/"),
-                Path.Combine(basePath, "../../../../../src/mono/dist/optimized/bcl/Facades/"),
+                Path.Combine(basePath, "../../../../../src/mono/dist/bcl/"),
+                Path.Combine(basePath, "../../../../../src/mono/dist/bcl/Facades/"),
             };
 
             var expectedContents = new[]