diff --git a/examples/WireMock.Net.Console.NETCoreApp3/WireMock.Net.Console.NETCoreApp3.csproj b/examples/WireMock.Net.Console.NETCoreApp3/WireMock.Net.Console.NETCoreApp3.csproj
index a0fed576..23b9b418 100644
--- a/examples/WireMock.Net.Console.NETCoreApp3/WireMock.Net.Console.NETCoreApp3.csproj
+++ b/examples/WireMock.Net.Console.NETCoreApp3/WireMock.Net.Console.NETCoreApp3.csproj
@@ -31,6 +31,7 @@
     <PackageReference Include="Handlebars.Net" Version="1.9.5" />
     <PackageReference Include="log4net" Version="2.0.8" />
     <PackageReference Include="Newtonsoft.Json" Version="11.0.2" />
+    <!--<PackageReference Include="Microsoft.CodeAnalysis.Scripting.Common" Version="3.4.0" />-->
   </ItemGroup>
 
   <ItemGroup>
diff --git a/examples/WireMock.Net.Console.Net452.Classic/MainApp.cs b/examples/WireMock.Net.Console.Net452.Classic/MainApp.cs
index fe9b9b20..2b92c007 100644
--- a/examples/WireMock.Net.Console.Net452.Classic/MainApp.cs
+++ b/examples/WireMock.Net.Console.Net452.Classic/MainApp.cs
@@ -11,6 +11,7 @@ using WireMock.RequestBuilders;
 using WireMock.ResponseBuilders;
 using WireMock.Server;
 using WireMock.Settings;
+using WireMock.Util;
 
 namespace WireMock.Net.ConsoleApplication
 {
@@ -515,6 +516,12 @@ namespace WireMock.Net.ConsoleApplication
                     .WithStatusCode(200)
                     .WithHeader("Content-Type", "application/json")
                     .WithBodyAsJson(new { Id = "5bdf076c-5654-4b3e-842c-7caf1fabf8c9" }));
+            server
+                .Given(Request.Create().WithPath("/random200or505").UsingGet())
+                .RespondWith(Response.Create().WithCallback(request => new ResponseMessage
+                {
+                    StatusCode = new Random().Next(1, 100) == 1 ? 504 : 200
+                }));
 
             System.Console.WriteLine(JsonConvert.SerializeObject(server.MappingModels, Formatting.Indented));
 
diff --git a/src/WireMock.Net.Abstractions/WireMock.Net.Abstractions.csproj b/src/WireMock.Net.Abstractions/WireMock.Net.Abstractions.csproj
index 85b1b2fa..590dc200 100644
--- a/src/WireMock.Net.Abstractions/WireMock.Net.Abstractions.csproj
+++ b/src/WireMock.Net.Abstractions/WireMock.Net.Abstractions.csproj
@@ -4,7 +4,7 @@
     <Description>Commonly used interfaces, models, enumerations and types.</Description>
     <AssemblyTitle>WireMock.Net.Abstractions</AssemblyTitle>
     <Authors>Stef Heyenrath</Authors>
-    <TargetFrameworks>netstandard1.0;netstandard2.0;net45</TargetFrameworks>
+    <TargetFrameworks>netstandard1.0;netstandard2.0;netstandard2.1;net45</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyName>WireMock.Net.Abstractions</AssemblyName>
     <PackageId>WireMock.Net.Abstractions</PackageId>
diff --git a/src/WireMock.Net.RestClient/WireMock.Net.RestClient.csproj b/src/WireMock.Net.RestClient/WireMock.Net.RestClient.csproj
index 5981f8a2..7e4cbffb 100644
--- a/src/WireMock.Net.RestClient/WireMock.Net.RestClient.csproj
+++ b/src/WireMock.Net.RestClient/WireMock.Net.RestClient.csproj
@@ -4,7 +4,7 @@
     <Description>A RestClient using RestEase to access the admin interface.</Description>
     <AssemblyTitle>WireMock.Net.RestClient</AssemblyTitle>
     <Authors>Stef Heyenrath</Authors>
-    <TargetFrameworks>netstandard1.1;netstandard2.0;net45</TargetFrameworks>
+    <TargetFrameworks>netstandard1.1;netstandard2.0;netstandard2.1;net45</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyName>WireMock.Net.RestClient</AssemblyName>
     <PackageId>WireMock.Net.RestClient</PackageId>
diff --git a/src/WireMock.Net.StandAlone/WireMock.Net.StandAlone.csproj b/src/WireMock.Net.StandAlone/WireMock.Net.StandAlone.csproj
index eb5acdac..d738a14c 100644
--- a/src/WireMock.Net.StandAlone/WireMock.Net.StandAlone.csproj
+++ b/src/WireMock.Net.StandAlone/WireMock.Net.StandAlone.csproj
@@ -3,7 +3,7 @@
     <Description>Lightweight StandAlone Http Mocking Server for .Net.</Description>
     <AssemblyTitle>WireMock.Net.StandAlone</AssemblyTitle>
     <Authors>Stef Heyenrath</Authors>
-    <TargetFrameworks>net451;net452;net46;net461;netstandard1.3;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>net451;net452;net46;net461;netstandard1.3;netstandard2.0;netstandard2.1</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyName>WireMock.Net.StandAlone</AssemblyName>
     <PackageId>WireMock.Net.StandAlone</PackageId>
@@ -36,7 +36,7 @@
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
   </PropertyGroup>
 
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' or '$(TargetFramework)' == 'netstandard2.0' ">
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'netstandard1.3' or '$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netstandard2.1' ">
     <DefineConstants>NETSTANDARD;USE_ASPNETCORE</DefineConstants>
   </PropertyGroup>
 
diff --git a/src/WireMock.Net/Matchers/CSharpCodeMatcher.cs b/src/WireMock.Net/Matchers/CSharpCodeMatcher.cs
index 30b5e217..dbf166ba 100644
--- a/src/WireMock.Net/Matchers/CSharpCodeMatcher.cs
+++ b/src/WireMock.Net/Matchers/CSharpCodeMatcher.cs
@@ -82,7 +82,7 @@ namespace WireMock.Matchers
 
             object result = null;
 
-#if NET451 || NET452
+#if (NET451 || NET452)
             var compilerParams = new System.CodeDom.Compiler.CompilerParameters
             {
                 GenerateInMemory = true,
@@ -122,36 +122,42 @@ namespace WireMock.Matchers
                 {
                     result = methodInfo.Invoke(helper, new[] { inputValue });
                 }
-                catch
+                catch (Exception ex)
                 {
-                    throw new WireMockException("CSharpCodeMatcher: Unable to call method 'IsMatch' in WireMock.CodeHelper");
+                    throw new WireMockException("CSharpCodeMatcher: Unable to call method 'IsMatch' in WireMock.CodeHelper", ex);
                 }
             }
-#elif NET46 || NET461
+#elif (NET46 || NET461)
             dynamic script;
             try
             {
                 script = CSScriptLibrary.CSScript.Evaluator.CompileCode(source).CreateObject("*");
             }
-            catch
+            catch (Exception ex)
             {
-                throw new WireMockException("CSharpCodeMatcher: Unable to create compiler for WireMock.CodeHelper");
+                throw new WireMockException("CSharpCodeMatcher: Unable to create compiler for WireMock.CodeHelper", ex);
             }
             
             try
             {
                 result = script.IsMatch(inputValue);
             }
-            catch
+            catch (Exception ex)
             {
-                throw new WireMockException("CSharpCodeMatcher: Problem calling method 'IsMatch' in WireMock.CodeHelper");
+                throw new WireMockException("CSharpCodeMatcher: Problem calling method 'IsMatch' in WireMock.CodeHelper", ex);
             }
-#elif NETSTANDARD2_0
+
+#elif (NETSTANDARD2_0 || NETSTANDARD2_1)
             dynamic script;
             try
             {
                 var assembly = CSScriptLib.CSScript.Evaluator.CompileCode(source);
+
+#if NETSTANDARD2_0
                 script = csscript.GenericExtensions.CreateObject(assembly, "*");
+#else
+                script = CSScriptLib.ReflectionExtensions.CreateObject(assembly,"*");
+#endif
             }
             catch (Exception ex)
             {
@@ -164,10 +170,10 @@ namespace WireMock.Matchers
             }
             catch (Exception ex)
             {
-                throw new WireMockException("CSharpCodeMatcher: Problem calling method 'IsMatch' in WireMock.CodeHelper");
+                throw new WireMockException("CSharpCodeMatcher: Problem calling method 'IsMatch' in WireMock.CodeHelper", ex);
             }
 #else
-            throw new NotSupportedException("The 'CSharpCodeMatcher' cannot be used in netstandard 1.3");
+                throw new NotSupportedException("The 'CSharpCodeMatcher' cannot be used in netstandard 1.3");
 #endif
             try
             {
diff --git a/src/WireMock.Net/Owin/AspNetCoreSelfHost.cs b/src/WireMock.Net/Owin/AspNetCoreSelfHost.cs
index 78bdf9c0..0732462d 100644
--- a/src/WireMock.Net/Owin/AspNetCoreSelfHost.cs
+++ b/src/WireMock.Net/Owin/AspNetCoreSelfHost.cs
@@ -139,6 +139,8 @@ namespace WireMock.Owin
                 _logger.Info("WireMock.Net server using netstandard1.3");
 #elif NETSTANDARD2_0
                 _logger.Info("WireMock.Net server using netstandard2.0");
+#elif NETSTANDARD2_1
+                _logger.Info("WireMock.Net server using netstandard2.1");
 #elif NET46
                 _logger.Info("WireMock.Net server using .net 4.6.1 or higher");
 #endif
diff --git a/src/WireMock.Net/Owin/HostUrlOptions.cs b/src/WireMock.Net/Owin/HostUrlOptions.cs
index 0cb3927b..cd404dd2 100644
--- a/src/WireMock.Net/Owin/HostUrlOptions.cs
+++ b/src/WireMock.Net/Owin/HostUrlOptions.cs
@@ -33,7 +33,7 @@ namespace WireMock.Owin
 
         private int FindFreeTcpPort()
         {
-#if USE_ASPNETCORE || NETSTANDARD2_0
+#if USE_ASPNETCORE || NETSTANDARD2_0 || NETSTANDARD2_1
             return 0;
 #else
             return PortUtils.FindFreeTcpPort();
diff --git a/src/WireMock.Net/WireMock.Net.csproj b/src/WireMock.Net/WireMock.Net.csproj
index a6b80f84..5245eb61 100644
--- a/src/WireMock.Net/WireMock.Net.csproj
+++ b/src/WireMock.Net/WireMock.Net.csproj
@@ -5,7 +5,7 @@
     <Authors>Stef Heyenrath</Authors>
     <!--<TargetFrameworks>net451;net452;net46;net461;netstandard1.3;netstandard2.0;netcoreapp2.1</TargetFrameworks>-->
     <!--<TargetFrameworks>net451;net452;net46;netstandard1.3;netstandard2.0</TargetFrameworks>-->
-    <TargetFrameworks>net451;net452;net46;net461;netstandard1.3;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>net451;net452;net46;net461;netstandard1.3;netstandard2.0;;netstandard2.1</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyName>WireMock.Net</AssemblyName>
     <PackageId>WireMock.Net</PackageId>
@@ -48,7 +48,7 @@
     <CodeAnalysisRuleSet>WireMock.Net.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>
 
-  <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard1.3' or '$(TargetFramework)' == 'netstandard2.0'">
+  <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard1.3' or '$(TargetFramework)' == 'netstandard2.0' or '$(TargetFramework)' == 'netstandard2.1'">
     <DefineConstants>NETSTANDARD;USE_ASPNETCORE</DefineConstants>
   </PropertyGroup>
 
@@ -140,6 +140,13 @@
     <PackageReference Include="CS-Script.Core" Version="1.1.1" />
   </ItemGroup>
 
+  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.1'">
+    <PackageReference Include="Microsoft.AspNetCore" Version="2.1.4" />
+
+    <!-- https://github.com/WireMock-Net/WireMock.Net/issues/448 -->
+    <PackageReference Include="CS-Script.Core" Version="1.3.1" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\WireMock.Net.Abstractions\WireMock.Net.Abstractions.csproj" />
   </ItemGroup>