diff --git a/PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20/PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20.csproj b/PSWinCom.Gateway.Client.MessageFormatters.NetStandard20/PSWinCom.Gateway.Client.MessageFormatters.NetStandard20.csproj
similarity index 95%
rename from PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20/PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20.csproj
rename to PSWinCom.Gateway.Client.MessageFormatters.NetStandard20/PSWinCom.Gateway.Client.MessageFormatters.NetStandard20.csproj
index e6672cc..48471a2 100644
--- a/PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20/PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20.csproj
+++ b/PSWinCom.Gateway.Client.MessageFormatters.NetStandard20/PSWinCom.Gateway.Client.MessageFormatters.NetStandard20.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <RootNamespace>PSWinCom.Gateway.Client.MessageFormatters</RootNamespace>
     <AssemblyName>PSWinCom.Gateway.Client.MessageFormatters</AssemblyName>
     <SignAssembly>true</SignAssembly>
diff --git a/PSWinCom.Gateway.Client.MessageFormatters.nuspec b/PSWinCom.Gateway.Client.MessageFormatters.nuspec
index 51921bc..5f3e427 100644
--- a/PSWinCom.Gateway.Client.MessageFormatters.nuspec
+++ b/PSWinCom.Gateway.Client.MessageFormatters.nuspec
@@ -19,6 +19,6 @@
     </metadata>
     <files>
         <file src="PSWinCom.Gateway.Client.MessageFormatters\bin\Release\PSWinCom.Gateway.Client.MessageFormatters.dll" target="lib\net35\PSWinCom.Gateway.Client.MessageFormatters.dll" />
-      <file src="PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20\bin\Release\netcoreapp2.0\PSWinCom.Gateway.Client.MessageFormatters.dll" target="lib\netcoreapp2.0\PSWinCom.Gateway.Client.MessageFormatters.dll" />
+      <file src="PSWinCom.Gateway.Client.MessageFormatters.NetStandard20\bin\Release\netstandard2.0\PSWinCom.Gateway.Client.MessageFormatters.dll" target="lib\netstandard2.0\PSWinCom.Gateway.Client.MessageFormatters.dll" />
     </files>
 </package>
diff --git a/PSWinCom.Gateway.Client.Mms.NetCoreApp2.0/PSWinCom.Gateway.Client.Mms.NetCoreApp2.0.csproj b/PSWinCom.Gateway.Client.Mms.NetStandard2.0/PSWinCom.Gateway.Client.Mms.NetStandard2.0.csproj
similarity index 83%
rename from PSWinCom.Gateway.Client.Mms.NetCoreApp2.0/PSWinCom.Gateway.Client.Mms.NetCoreApp2.0.csproj
rename to PSWinCom.Gateway.Client.Mms.NetStandard2.0/PSWinCom.Gateway.Client.Mms.NetStandard2.0.csproj
index b793b60..885d4f1 100644
--- a/PSWinCom.Gateway.Client.Mms.NetCoreApp2.0/PSWinCom.Gateway.Client.Mms.NetCoreApp2.0.csproj
+++ b/PSWinCom.Gateway.Client.Mms.NetStandard2.0/PSWinCom.Gateway.Client.Mms.NetStandard2.0.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <AssemblyName>PSWinCom.Gateway.Client.Mms</AssemblyName>
     <SignAssembly>true</SignAssembly>
     <DelaySign>false</DelaySign>
@@ -15,7 +15,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="SharpZipLib" Version="1.0.0-alpha2" />
+    <PackageReference Include="SharpZipLib" Version="1.0.0" />
   </ItemGroup>
 
 </Project>
diff --git a/PSWinCom.Gateway.Client.Mms.nuspec b/PSWinCom.Gateway.Client.Mms.nuspec
index b2138b7..cec890a 100644
--- a/PSWinCom.Gateway.Client.Mms.nuspec
+++ b/PSWinCom.Gateway.Client.Mms.nuspec
@@ -23,6 +23,6 @@
     <files>
         <file src="net20\MMSClient\Client\bin\Release\PSWinCom.Gateway.MMS.Client.dll" target="lib\net20\PSWinCom.Gateway.MMS.Client.dll" />       
         <file src="PSWinCom.Gateway.Client.Mms\bin\Release\PSWinCom.Gateway.Client.Mms.dll" target="lib\net35\PSWinCom.Gateway.Client.Mms.dll" />
-        <file src="PSWinCom.Gateway.Client.Mms.NetCoreApp2.0\bin\Release\netcoreapp2.0\PSWinCom.Gateway.Client.Mms.dll" target="lib\netcoreapp2.0\PSWinCom.Gateway.Client.Mms.dll" />
+        <file src="PSWinCom.Gateway.Client.Mms.NetStandard2.0\bin\Release\netstandard2.0\PSWinCom.Gateway.Client.Mms.dll" target="lib\netstandard2.0\PSWinCom.Gateway.Client.Mms.dll" />
     </files>
 </package>
diff --git a/PSWinCom.Gateway.Client.NetCoreApp20.Tests/PSWinCom.Gateway.Client.NetCoreApp20.Tests.csproj b/PSWinCom.Gateway.Client.NetStandard20.Tests/PSWinCom.Gateway.Client.NetStandard20.Tests.csproj
similarity index 79%
rename from PSWinCom.Gateway.Client.NetCoreApp20.Tests/PSWinCom.Gateway.Client.NetCoreApp20.Tests.csproj
rename to PSWinCom.Gateway.Client.NetStandard20.Tests/PSWinCom.Gateway.Client.NetStandard20.Tests.csproj
index d5a20e0..6a2a4ff 100644
--- a/PSWinCom.Gateway.Client.NetCoreApp20.Tests/PSWinCom.Gateway.Client.NetCoreApp20.Tests.csproj
+++ b/PSWinCom.Gateway.Client.NetStandard20.Tests/PSWinCom.Gateway.Client.NetStandard20.Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFrameworks>netcoreapp2.1;net461</TargetFrameworks>
     <SignAssembly>true</SignAssembly>
     <AssemblyOriginatorKeyFile>..\gateway_client.snk</AssemblyOriginatorKeyFile>
     <DelaySign>false</DelaySign>
@@ -19,13 +19,14 @@
 
   <ItemGroup>
     <PackageReference Include="FluentAssertions" Version="5.4.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
     <PackageReference Include="Moq" Version="4.8.2" />
     <PackageReference Include="NUnit" Version="3.10.1" />
-    <PackageReference Include="Should" Version="1.1.20" />
+    <PackageReference Include="NUnit3TestAdapter" Version="3.10.0" />
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="..\PSWinCom.Gateway.Client.NetCoreApp20\PSWinCom.Gateway.Client.NetCoreApp20.csproj" />
+    <ProjectReference Include="..\PSWinCom.Gateway.Client.NetStandard20\PSWinCom.Gateway.Client.NetStandard20.csproj" />
   </ItemGroup>
 
 </Project>
diff --git a/PSWinCom.Gateway.Client.NetCoreApp20/Internals.cs b/PSWinCom.Gateway.Client.NetStandard20/Internals.cs
similarity index 64%
rename from PSWinCom.Gateway.Client.NetCoreApp20/Internals.cs
rename to PSWinCom.Gateway.Client.NetStandard20/Internals.cs
index c8d7804..ab0c4e8 100644
--- a/PSWinCom.Gateway.Client.NetCoreApp20/Internals.cs
+++ b/PSWinCom.Gateway.Client.NetStandard20/Internals.cs
@@ -1,6 +1,6 @@
 using System.Runtime.CompilerServices;
 
-[assembly: InternalsVisibleTo("PSWinCom.Gateway.Client.NetCoreApp20.Tests, PublicKey=002400000480000094000000060200000024000052534131000400000100010089fb6d20de27a9" +
+[assembly: InternalsVisibleTo("PSWinCom.Gateway.Client.NetStandard20.Tests, PublicKey=002400000480000094000000060200000024000052534131000400000100010089fb6d20de27a9" +
 "88eb2f16ab37f786c99470fb49a760205fb1c35d26a8c0abd616868a81400c13c78d4229b3cdbf" +
 "7285cf5af8e358d60ceb8e730c21975de5537ee7d0ccc4519ca9277fa828124e66bdb48c500a4b" +
 "bee93dcf05f965c24aca3cc6c510a3eb8fc23c36c67945346f45c62ba2b046ed01334775c5feff" +
diff --git a/PSWinCom.Gateway.Client.NetCoreApp20/PSWinCom.Gateway.Client.NetCoreApp20.csproj b/PSWinCom.Gateway.Client.NetStandard20/PSWinCom.Gateway.Client.NetStandard20.csproj
similarity index 95%
rename from PSWinCom.Gateway.Client.NetCoreApp20/PSWinCom.Gateway.Client.NetCoreApp20.csproj
rename to PSWinCom.Gateway.Client.NetStandard20/PSWinCom.Gateway.Client.NetStandard20.csproj
index 3e7eacc..d1ca483 100644
--- a/PSWinCom.Gateway.Client.NetCoreApp20/PSWinCom.Gateway.Client.NetCoreApp20.csproj
+++ b/PSWinCom.Gateway.Client.NetStandard20/PSWinCom.Gateway.Client.NetStandard20.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFramework>netstandard2.0</TargetFramework>
     <AssemblyName>PSWinCom.Gateway.Client</AssemblyName>
     <RootNamespace>PSWinCom.Gateway.Client</RootNamespace>
     <Company>LINK Mobility AS</Company>
@@ -67,11 +67,5 @@
     <Folder Include="Properties\" />
     <Folder Include="Transports\" />
   </ItemGroup>
-
-  <ItemGroup>
-    <Reference Include="System">
-      <HintPath>System</HintPath>
-    </Reference>
-  </ItemGroup>
   
 </Project>
diff --git a/PSWinCom.Gateway.Client.Tests/HttpTransportTests.cs b/PSWinCom.Gateway.Client.Tests/HttpTransportTests.cs
index 865ac5b..eb8a8cd 100644
--- a/PSWinCom.Gateway.Client.Tests/HttpTransportTests.cs
+++ b/PSWinCom.Gateway.Client.Tests/HttpTransportTests.cs
@@ -4,11 +4,11 @@
 using System.Text;
 using System.Threading.Tasks;
 using NUnit.Framework;
-using Should;
 using Moq;
 using System.Xml.Linq;
 using System.Net;
 using System.IO;
+using FluentAssertions;
 
 namespace PSWinCom.Gateway.Client.Tests
 {
@@ -31,10 +31,10 @@ public void Should_pass_on_xml()
                     transport
                         .Send(document)
                         .Success
-                        .ShouldBeFalse();
+                        .Should().BeFalse();
                     request
                         .Result
-                        .ShouldEqual(expected_string_representation_of(document));
+                        .Should().Be(expected_string_representation_of(document));
                 }
             );
         }
@@ -50,7 +50,7 @@ public void Should_return_success_when_status_code_is_200()
                     transport
                         .Send(new XDocument(new XElement("TEST")))
                         .Success
-                        .ShouldBeTrue();
+                        .Should().BeTrue();
                 }
             );
         }
@@ -65,7 +65,7 @@ public void Should_return_response_content_of_successful_request()
                 {
                     transport
                         .Send(new XDocument(new XElement("TEST")))
-                        .Content.Root.Name.ShouldEqual("ROOT");
+                        .Content.Root.Name.Should().Be("ROOT");
                         
                 }
             );
@@ -116,11 +116,13 @@ private static Task<string> listener(string at, int that_returns, XDocument with
         }
         private string expected_string_representation_of(XDocument document)
         {
+            document.Declaration = new XDeclaration("1.0", "iso8859-1", null);
+            
             using (var expectedStream = new MemoryStream())
             {
                 document.Save(expectedStream);
                 expectedStream.Seek(0, SeekOrigin.Begin);
-                return new StreamReader(expectedStream).ReadToEnd();
+                return new StreamReader(expectedStream, Encoding.GetEncoding("iso8859-1")).ReadToEnd();
             }
         }
     }
diff --git a/PSWinCom.Gateway.Client.Tests/Properties/AssemblyInfo.cs b/PSWinCom.Gateway.Client.Tests/Properties/AssemblyInfo.cs
index 7450707..5d0c17f 100644
--- a/PSWinCom.Gateway.Client.Tests/Properties/AssemblyInfo.cs
+++ b/PSWinCom.Gateway.Client.Tests/Properties/AssemblyInfo.cs
@@ -35,7 +35,7 @@
 [assembly: AssemblyVersion("1.0.0.0")]
 [assembly: AssemblyFileVersion("1.0.0.0")]
 
-[assembly: InternalsVisibleTo("PSWinCom.Gateway.Client.NetCoreApp20.Tests, PublicKey=002400000480000094000000060200000024000052534131000400000100010089fb6d20de27a9" +
+[assembly: InternalsVisibleTo("PSWinCom.Gateway.Client.NetStandard20.Tests, PublicKey=002400000480000094000000060200000024000052534131000400000100010089fb6d20de27a9" +
 "88eb2f16ab37f786c99470fb49a760205fb1c35d26a8c0abd616868a81400c13c78d4229b3cdbf" +
 "7285cf5af8e358d60ceb8e730c21975de5537ee7d0ccc4519ca9277fa828124e66bdb48c500a4b" +
 "bee93dcf05f965c24aca3cc6c510a3eb8fc23c36c67945346f45c62ba2b046ed01334775c5feff" +
diff --git a/PSWinCom.Gateway.Client.Tests/SendAsyncTests.cs b/PSWinCom.Gateway.Client.Tests/SendAsyncTests.cs
index 1dbeb42..9ee6cfc 100644
--- a/PSWinCom.Gateway.Client.Tests/SendAsyncTests.cs
+++ b/PSWinCom.Gateway.Client.Tests/SendAsyncTests.cs
@@ -30,7 +30,7 @@ public void Should_throw_exception_when_trying_to_call_async_send_with_no_async_
         }
 
         [Test]
-        public async void Should_be_able_to_send_with_async_transport()
+        public async Task Should_be_able_to_send_with_async_transport()
         {
             var client = new PSWinCom.Gateway.Client.GatewayClient(mockAsyncTransport.Object);
 
diff --git a/PSWinCom.Gateway.Client.nuspec b/PSWinCom.Gateway.Client.nuspec
index 89a7b88..8892a5e 100644
--- a/PSWinCom.Gateway.Client.nuspec
+++ b/PSWinCom.Gateway.Client.nuspec
@@ -16,6 +16,6 @@
         <file src="PSWinCom.Gateway.Client\bin\Release\PSWinCom.Gateway.Client.dll" target="lib\net45\PSWinCom.Gateway.Client.dll" />
         <file src="PSWinCom.Gateway.Client.Net40\bin\Release\PSWinCom.Gateway.Client.dll" target="lib\net40\PSWinCom.Gateway.Client.dll" />
         <file src="PSWinCom.Gateway.Client.Net35\bin\Release\PSWinCom.Gateway.Client.Net35.dll" target="lib\net35\PSWinCom.Gateway.Client.dll" />
-        <file src="PSWinCom.Gateway.Client.NetCoreApp20\bin\Release\netcoreapp2.0\PSWinCom.Gateway.Client.dll" target="lib\netcoreapp2.0\PSWinCom.Gateway.Client.dll" />
+        <file src="PSWinCom.Gateway.Client.NetStandard20\bin\Release\netstandard2.0\PSWinCom.Gateway.Client.dll" target="lib\netstandard2.0\PSWinCom.Gateway.Client.dll" />
     </files>
 </package>
diff --git a/PSWinCom.Gateway.Client.sln b/PSWinCom.Gateway.Client.sln
index 6de9aaf..c7571b6 100644
--- a/PSWinCom.Gateway.Client.sln
+++ b/PSWinCom.Gateway.Client.sln
@@ -55,23 +55,23 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Net40", "Net40", "{C9B6EECF
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PSWinCom.Gateway.Client.Net40", "PSWinCom.Gateway.Client.Net40\PSWinCom.Gateway.Client.Net40.csproj", "{CA463012-660D-4232-A38E-9B9A2905CCEC}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "NetCoreApp20", "NetCoreApp20", "{FDFB11D8-27D3-487C-BA0A-6C7CED30C844}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "NetStandard20", "NetStandard20", "{FDFB11D8-27D3-487C-BA0A-6C7CED30C844}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "NetCoreApp2.0", "NetCoreApp2.0", "{C5357CA1-4D68-40E6-9DEB-45F74916607E}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "NetStandard2.0", "NetStandard2.0", "{C5357CA1-4D68-40E6-9DEB-45F74916607E}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PSWinCom.Gateway.Client.Mms.NetCoreApp2.0", "PSWinCom.Gateway.Client.Mms.NetCoreApp2.0\PSWinCom.Gateway.Client.Mms.NetCoreApp2.0.csproj", "{F823A8C4-C0A8-456C-85F1-14016120B7C9}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PSWinCom.Gateway.Client.Mms.NetStandard2.0", "PSWinCom.Gateway.Client.Mms.NetStandard2.0\PSWinCom.Gateway.Client.Mms.NetStandard2.0.csproj", "{F823A8C4-C0A8-456C-85F1-14016120B7C9}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Client", "Client", "{AC9B4CE1-6F94-4B34-81EB-DE4EA4FCA76A}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PSWinCom.Gateway.Client.NetCoreApp20", "PSWinCom.Gateway.Client.NetCoreApp20\PSWinCom.Gateway.Client.NetCoreApp20.csproj", "{F21ABECD-3959-4D4E-BA8D-1E27B4033FAF}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PSWinCom.Gateway.Client.NetStandard20", "PSWinCom.Gateway.Client.NetStandard20\PSWinCom.Gateway.Client.NetStandard20.csproj", "{F21ABECD-3959-4D4E-BA8D-1E27B4033FAF}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PSWinCom.Gateway.Client.NetCoreApp20.Tests", "PSWinCom.Gateway.Client.NetCoreApp20.Tests\PSWinCom.Gateway.Client.NetCoreApp20.Tests.csproj", "{93424367-C710-4A91-8378-D153036F3808}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PSWinCom.Gateway.Client.NetStandard20.Tests", "PSWinCom.Gateway.Client.NetStandard20.Tests\PSWinCom.Gateway.Client.NetStandard20.Tests.csproj", "{93424367-C710-4A91-8378-D153036F3808}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Net35", "Net35", "{CFB2C6D3-1B1C-4EE7-AD6C-FA43D1EE86B9}"
 EndProject
-Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "NetCoreApp20", "NetCoreApp20", "{C63B06A7-75FB-462B-8C74-CCCD45054BCA}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "NetStandard20", "NetStandard20", "{C63B06A7-75FB-462B-8C74-CCCD45054BCA}"
 EndProject
-Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20", "PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20\PSWinCom.Gateway.Client.MessageFormatters.NetCoreApp20.csproj", "{2DFDA8A5-BD8C-4EB7-ACC1-888CF03840EB}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "PSWinCom.Gateway.Client.MessageFormatters.NetStandard20", "PSWinCom.Gateway.Client.MessageFormatters.NetStandard20\PSWinCom.Gateway.Client.MessageFormatters.NetStandard20.csproj", "{2DFDA8A5-BD8C-4EB7-ACC1-888CF03840EB}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution