diff --git a/ClosedXML/ClosedXML.csproj b/ClosedXML/ClosedXML.csproj
index 6ef1459..26cb10b 100644
--- a/ClosedXML/ClosedXML.csproj
+++ b/ClosedXML/ClosedXML.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net452;net461</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net40;net461</TargetFrameworks>
     <Version>0.9</Version>
     <Authors>Manuel de Leon, Amir Ghezelbash, Francois Botha</Authors>
     <Company />
@@ -17,8 +17,8 @@
     <DefineConstants>$(DefineConstants);_NETSTANDARD_;_NETSTANDARD2_0_</DefineConstants>
   </PropertyGroup>
 
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'net452' ">
-    <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET452_</DefineConstants>
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net40' ">
+    <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET40_</DefineConstants>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net461' ">
@@ -34,7 +34,7 @@
     <PackageReference Include="System.IO.Packaging" Version="4.4.0" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'net452'">
+  <ItemGroup Condition="'$(TargetFramework)' == 'net40'">
     <PackageReference Include="DocumentFormat.OpenXml" Version="2.7.2" />
     <Reference Include="WindowsBase" />
   </ItemGroup>
diff --git a/ClosedXML_Examples/ClosedXML_Examples.csproj b/ClosedXML_Examples/ClosedXML_Examples.csproj
index b7d0223..47defdd 100644
--- a/ClosedXML_Examples/ClosedXML_Examples.csproj
+++ b/ClosedXML_Examples/ClosedXML_Examples.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452;net461</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net40;net461</TargetFrameworks>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(TargetFramework)' == 'netstandard1.6' ">
@@ -12,8 +12,8 @@
     <DefineConstants>$(DefineConstants);_NETSTANDARD_;_NETSTANDARD2_0_</DefineConstants>
   </PropertyGroup>
 
-  <PropertyGroup Condition=" '$(TargetFramework)' == 'net452' ">
-    <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET452_</DefineConstants>
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net40' ">
+    <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET40_</DefineConstants>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net461' ">
diff --git a/ClosedXML_Sandbox/ClosedXML_Sandbox.csproj b/ClosedXML_Sandbox/ClosedXML_Sandbox.csproj
index 35397d6..df514a3 100644
--- a/ClosedXML_Sandbox/ClosedXML_Sandbox.csproj
+++ b/ClosedXML_Sandbox/ClosedXML_Sandbox.csproj
@@ -2,7 +2,19 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>netcoreapp2.0;net452;net461</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net40;net461</TargetFrameworks>
+  </PropertyGroup>
+
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
+    <DefineConstants>$(DefineConstants);_NETSTANDARD_;_NETSTANDARD2_0_</DefineConstants>
+  </PropertyGroup>
+
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net40' ">
+    <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET40_</DefineConstants>
+  </PropertyGroup>
+
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net461' ">
+    <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET461_</DefineConstants>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/ClosedXML_Sandbox/ReflectionExtensions.cs b/ClosedXML_Sandbox/ReflectionExtensions.cs
new file mode 100644
index 0000000..7229a8c
--- /dev/null
+++ b/ClosedXML_Sandbox/ReflectionExtensions.cs
@@ -0,0 +1,17 @@
+#if _NET40_
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text;
+
+namespace ClosedXML_Sandbox
+{
+    internal static class ReflectionExtensions
+    {
+        public static void SetValue(this PropertyInfo info, object obj, object value)
+        {
+            info.SetValue(obj, value, null);
+        }
+    }
+}
+#endif
diff --git a/ClosedXML_Tests/ClosedXML_Tests.csproj b/ClosedXML_Tests/ClosedXML_Tests.csproj
index efe9be7..3cae8d7 100644
--- a/ClosedXML_Tests/ClosedXML_Tests.csproj
+++ b/ClosedXML_Tests/ClosedXML_Tests.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452;net461</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net40;net452;net461</TargetFrameworks>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
@@ -17,6 +17,10 @@
     <DefineConstants>$(DefineConstants);_NETSTANDARD_;_NETSTANDARD2_0_</DefineConstants>
   </PropertyGroup>
 
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net40' ">
+    <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET40_</DefineConstants>
+  </PropertyGroup>
+
   <PropertyGroup Condition=" '$(TargetFramework)' == 'net452' ">
     <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET452_</DefineConstants>
   </PropertyGroup>
@@ -25,26 +29,35 @@
     <DefineConstants>$(DefineConstants);_NETFRAMEWORK_;_NET461_</DefineConstants>
   </PropertyGroup>
 
+
+
   <ItemGroup>
     <EmbeddedResource Include="**\*.xlsx" />
     <EmbeddedResource Include="Resource\Images\*.png" />
     <EmbeddedResource Include="Resource\Images\*.jpg" />
   </ItemGroup>
 
-
-  <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0" />
+  <ItemGroup Condition=" '$(TargetFramework)' != 'net40' ">
     <PackageReference Include="MSTest.TestAdapter" Version="1.1.17" />
     <PackageReference Include="MSTest.TestFramework" Version="1.1.17" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0" />
+  </ItemGroup>
+
+  <ItemGroup>
     <PackageReference Include="NUnit" Version="3.7.1" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.8.0" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'netcoreapp2.0'">
     <PackageReference Include="System.Data.Common" Version="4.3.0" />
+    <PackageReference Include="DocumentFormat.OpenXml" Version="2.7.2" />
     <PackageReference Include="System.IO.Packaging" Version="4.4.0" />
   </ItemGroup>
 
+  <ItemGroup Condition="'$(TargetFramework)' == 'net40'">
+    <Reference Include="WindowsBase" />
+  </ItemGroup>
+
   <ItemGroup Condition="'$(TargetFramework)' == 'net452'">
     <Reference Include="WindowsBase" />
   </ItemGroup>
diff --git a/appveyor.yml b/appveyor.yml
index 92db23d..b79f00a 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -40,5 +40,6 @@
   - nuget restore
 
 artifacts:
-  - path: ClosedXML/bin/Release/net452/ClosedXML.dll
+  - path: ClosedXML/bin/Release/netstandard2.0/ClosedXML.dll
+  - path: ClosedXML/bin/Release/net40/ClosedXML.dll
   - path: ClosedXML/bin/Release/net461/ClosedXML.dll