diff --git a/src/Microsoft.Blazor.Browser.JS/Microsoft.Blazor.Browser.JS.csproj b/src/Microsoft.Blazor.Browser.JS/Microsoft.Blazor.Browser.JS.csproj
index 3418b3585f..faab5e6edc 100644
--- a/src/Microsoft.Blazor.Browser.JS/Microsoft.Blazor.Browser.JS.csproj
+++ b/src/Microsoft.Blazor.Browser.JS/Microsoft.Blazor.Browser.JS.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <TypeScriptCompileBlocked>true</TypeScriptCompileBlocked>
     <TypeScriptToolsVersion>Latest</TypeScriptToolsVersion>
     <DefaultItemExcludes>${DefaultItemExcludes};node_modules\**</DefaultItemExcludes>
diff --git a/src/Microsoft.Blazor.Build/Core/FileSystem/IndexHtmlFileProvider.cs b/src/Microsoft.Blazor.Build/Core/FileSystem/IndexHtmlFileProvider.cs
index a3570738f7..cd9a644139 100644
--- a/src/Microsoft.Blazor.Build/Core/FileSystem/IndexHtmlFileProvider.cs
+++ b/src/Microsoft.Blazor.Build/Core/FileSystem/IndexHtmlFileProvider.cs
@@ -41,7 +41,7 @@ namespace Microsoft.Blazor.Build.Core.FileSystem
             var referenceNames = binFiles
                 .Where(file => !string.Equals(file.Name, assemblyNameWithExtension))
                 .Select(file => file.Name);
-            var referencesAttribute = string.Join(',', referenceNames.ToArray());
+            var referencesAttribute = string.Join(",", referenceNames.ToArray());
 
             return $"<script src=\"/_framework/blazor.js\"" +
                    $" main=\"{assemblyNameWithExtension}\"" +
diff --git a/src/Microsoft.Blazor.BuildTools/Microsoft.Blazor.BuildTools.csproj b/src/Microsoft.Blazor.BuildTools/Microsoft.Blazor.BuildTools.csproj
index 31a949002a..e117f9f832 100644
--- a/src/Microsoft.Blazor.BuildTools/Microsoft.Blazor.BuildTools.csproj
+++ b/src/Microsoft.Blazor.BuildTools/Microsoft.Blazor.BuildTools.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <OutputType>Exe</OutputType>
     <OutDir>tools</OutDir>
   </PropertyGroup>
diff --git a/src/Microsoft.Blazor.Common/FileProviders/CompositeMountedFileProvider.cs b/src/Microsoft.Blazor.Common/FileProviders/CompositeMountedFileProvider.cs
index a428062146..7e24ac2586 100644
--- a/src/Microsoft.Blazor.Common/FileProviders/CompositeMountedFileProvider.cs
+++ b/src/Microsoft.Blazor.Common/FileProviders/CompositeMountedFileProvider.cs
@@ -44,12 +44,12 @@ namespace Microsoft.Blazor.Internal.Common.FileProviders
             {
                 _file = file;
 
-                if (!file.PhysicalPath.StartsWith('/'))
+                if (!file.PhysicalPath.StartsWith("/"))
                 {
                     throw new ArgumentException($"For mounted files, {nameof(file.PhysicalPath)} must start with '/'. Value supplied: '{file.PhysicalPath}'.");
                 }
 
-                if (!mountPoint.StartsWith('/'))
+                if (!mountPoint.StartsWith("/"))
                 {
                     throw new ArgumentException("The path must start with '/'", nameof(mountPoint));
                 }
@@ -60,7 +60,7 @@ namespace Microsoft.Blazor.Internal.Common.FileProviders
                 }
                 else
                 {
-                    if (mountPoint.EndsWith('/'))
+                    if (mountPoint.EndsWith("/"))
                     {
                         throw new ArgumentException("Non-root paths must not end with '/'", nameof(mountPoint));
                     }
diff --git a/src/Microsoft.Blazor.Common/FileProviders/InMemoryFileProvider.cs b/src/Microsoft.Blazor.Common/FileProviders/InMemoryFileProvider.cs
index 0367e9d91e..8a2b4736ac 100644
--- a/src/Microsoft.Blazor.Common/FileProviders/InMemoryFileProvider.cs
+++ b/src/Microsoft.Blazor.Common/FileProviders/InMemoryFileProvider.cs
@@ -18,7 +18,7 @@ namespace Microsoft.Blazor.Internal.Common.FileProviders
         private readonly IDictionary<string, InMemoryDirectoryContents> _directoriesByFullPath;
 
         // It's convenient to use forward slash, because it matches URL conventions
-        public const char DirectorySeparatorChar = '/';
+        public const string DirectorySeparatorChar = "/";
 
         public InMemoryFileProvider(IEnumerable<(string, byte[])> contents) : this(
             contents.Select(pair => InMemoryFileInfo
diff --git a/src/Microsoft.Blazor.Common/Microsoft.Blazor.Common.csproj b/src/Microsoft.Blazor.Common/Microsoft.Blazor.Common.csproj
index a9519032ba..93783ee074 100644
--- a/src/Microsoft.Blazor.Common/Microsoft.Blazor.Common.csproj
+++ b/src/Microsoft.Blazor.Common/Microsoft.Blazor.Common.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/Microsoft.Blazor.Mono/Microsoft.Blazor.Mono.csproj b/src/Microsoft.Blazor.Mono/Microsoft.Blazor.Mono.csproj
index ab0a15aa4d..0f727a25aa 100644
--- a/src/Microsoft.Blazor.Mono/Microsoft.Blazor.Mono.csproj
+++ b/src/Microsoft.Blazor.Mono/Microsoft.Blazor.Mono.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\mono\mono.targets" />
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
 
   <ItemGroup>