diff --git a/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj b/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
index 2ba1c4089..2de1c7897 100644
--- a/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
+++ b/ICSharpCode.Decompiler/ICSharpCode.Decompiler.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
+<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
   <PropertyGroup>
     <ProjectGuid>{984CC812-9470-4A13-AFF9-CC44068D666C}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -7,7 +7,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>ICSharpCode.Decompiler</RootNamespace>
     <AssemblyName>ICSharpCode.Decompiler</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <TargetFrameworkProfile>
     </TargetFrameworkProfile>
     <AppDesignerFolder>Properties</AppDesignerFolder>
diff --git a/ICSharpCode.Decompiler/IL/ILOpCodes.cs b/ICSharpCode.Decompiler/IL/ILOpCodes.cs
index 7a9f59aaa..f6a5bfb34 100644
--- a/ICSharpCode.Decompiler/IL/ILOpCodes.cs
+++ b/ICSharpCode.Decompiler/IL/ILOpCodes.cs
@@ -16,6 +16,7 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
+using System;
 namespace ICSharpCode.Decompiler.IL
 {
 	enum ILOpCode : ushort
diff --git a/ICSharpCode.Decompiler/Tests/ICSharpCode.Decompiler.Tests.csproj b/ICSharpCode.Decompiler/Tests/ICSharpCode.Decompiler.Tests.csproj
index 4c24bf125..b1928b085 100644
--- a/ICSharpCode.Decompiler/Tests/ICSharpCode.Decompiler.Tests.csproj
+++ b/ICSharpCode.Decompiler/Tests/ICSharpCode.Decompiler.Tests.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
+<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
   <PropertyGroup>
     <ProjectGuid>{FEC0DA52-C4A6-4710-BE36-B484A20C5E22}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -7,7 +7,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>ICSharpCode.Decompiler.Tests</RootNamespace>
     <AssemblyName>ICSharpCode.Decompiler.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <NoStdLib>False</NoStdLib>
diff --git a/ICSharpCode.Decompiler/Tests/app.config b/ICSharpCode.Decompiler/Tests/app.config
index 95419741b..5095b0e47 100644
--- a/ICSharpCode.Decompiler/Tests/app.config
+++ b/ICSharpCode.Decompiler/Tests/app.config
@@ -1,11 +1,14 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <runtime>
     <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
       <dependentAssembly>
-        <assemblyIdentity name="System.Collections.Immutable" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-        <bindingRedirect oldVersion="0.0.0.0-1.2.1.0" newVersion="1.2.1.0" />
+        <assemblyIdentity name="System.Collections.Immutable" publicKeyToken="b03f5f7f11d50a3a" culture="neutral"/>
+        <bindingRedirect oldVersion="0.0.0.0-1.2.1.0" newVersion="1.2.1.0"/>
       </dependentAssembly>
     </assemblyBinding>
   </runtime>
-</configuration>
\ No newline at end of file
+  <startup>
+    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1"/>
+  </startup>
+</configuration>
diff --git a/ICSharpCode.Decompiler/Tests/packages.config b/ICSharpCode.Decompiler/Tests/packages.config
index d7dfdd7e6..0c6a35b9e 100644
--- a/ICSharpCode.Decompiler/Tests/packages.config
+++ b/ICSharpCode.Decompiler/Tests/packages.config
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="DiffLib" version="1.0.0.55" />
+  <package id="DiffLib" version="1.0.0.55" requireReinstallation="true" />
   <package id="Microsoft.CodeAnalysis.Analyzers" version="1.1.0" targetFramework="net45" />
   <package id="Microsoft.CodeAnalysis.Common" version="1.3.2" targetFramework="net45" />
   <package id="Microsoft.CodeAnalysis.CSharp" version="1.3.2" targetFramework="net45" />
diff --git a/ILSpy.AddIn/ILSpy.AddIn.csproj b/ILSpy.AddIn/ILSpy.AddIn.csproj
index e4ae05576..7e7eef4a4 100644
--- a/ILSpy.AddIn/ILSpy.AddIn.csproj
+++ b/ILSpy.AddIn/ILSpy.AddIn.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="4.0">
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="12.0">
   <PropertyGroup>
     <!-- Use the SDK for the current version of Visual Studio -->
     <VsSdkTargets Condition="'$(VisualStudioVersion)'!=''">$(MSBuildExtensionsPath)\Microsoft\VisualStudio\v$(VisualStudioVersion)\VSSDK\Microsoft.VsSDK.targets</VsSdkTargets>
@@ -23,7 +23,7 @@
     <AssemblyName>ILSpy.AddIn</AssemblyName>
     <SignAssembly>True</SignAssembly>
     <AssemblyOriginatorKeyFile>Key.snk</AssemblyOriginatorKeyFile>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
   </PropertyGroup>
   <PropertyGroup>
     <!-- Common debugging support -->
diff --git a/ILSpy.AddIn/Resources.Designer.cs b/ILSpy.AddIn/Resources.Designer.cs
index 646632f04..7fd7fbc44 100644
--- a/ILSpy.AddIn/Resources.Designer.cs
+++ b/ILSpy.AddIn/Resources.Designer.cs
@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Runtime Version:4.0.30319.35317
+//     Runtime Version:4.0.30319.42000
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.
@@ -19,7 +19,7 @@ namespace ICSharpCode.ILSpy.AddIn {
     // class via a tool like ResGen or Visual Studio.
     // To add or remove a member, edit your .ResX file then rerun ResGen
     // with the /str option, or rebuild your VS project.
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "4.0.0.0")]
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "15.0.0.0")]
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
     internal class Resources {
diff --git a/ILSpy.BamlDecompiler/ILSpy.BamlDecompiler.csproj b/ILSpy.BamlDecompiler/ILSpy.BamlDecompiler.csproj
index a5be0206f..6f547027f 100644
--- a/ILSpy.BamlDecompiler/ILSpy.BamlDecompiler.csproj
+++ b/ILSpy.BamlDecompiler/ILSpy.BamlDecompiler.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
+<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
   <PropertyGroup>
     <ProjectGuid>{A6BAD2BA-76BA-461C-8B6D-418607591247}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -7,7 +7,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>ILSpy.BamlDecompiler</RootNamespace>
     <AssemblyName>ILSpy.BamlDecompiler.Plugin</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <TargetFrameworkProfile>
     </TargetFrameworkProfile>
     <AppDesignerFolder>Properties</AppDesignerFolder>
diff --git a/ILSpy.BamlDecompiler/Tests/ILSpy.BamlDecompiler.Tests.csproj b/ILSpy.BamlDecompiler/Tests/ILSpy.BamlDecompiler.Tests.csproj
index c4ec4bb86..8ed22ad5f 100644
--- a/ILSpy.BamlDecompiler/Tests/ILSpy.BamlDecompiler.Tests.csproj
+++ b/ILSpy.BamlDecompiler/Tests/ILSpy.BamlDecompiler.Tests.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
+<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
   <PropertyGroup>
     <ProjectGuid>{1169E6D1-1899-43D4-A500-07CE4235B388}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -7,7 +7,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>ILSpy.BamlDecompiler.Tests</RootNamespace>
     <AssemblyName>ILSpy.BamlDecompiler.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <TargetFrameworkProfile>
     </TargetFrameworkProfile>
     <AllowUnsafeBlocks>False</AllowUnsafeBlocks>
diff --git a/ILSpy.BamlDecompiler/Tests/app.config b/ILSpy.BamlDecompiler/Tests/app.config
index 95419741b..5095b0e47 100644
--- a/ILSpy.BamlDecompiler/Tests/app.config
+++ b/ILSpy.BamlDecompiler/Tests/app.config
@@ -1,11 +1,14 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <runtime>
     <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
       <dependentAssembly>
-        <assemblyIdentity name="System.Collections.Immutable" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
-        <bindingRedirect oldVersion="0.0.0.0-1.2.1.0" newVersion="1.2.1.0" />
+        <assemblyIdentity name="System.Collections.Immutable" publicKeyToken="b03f5f7f11d50a3a" culture="neutral"/>
+        <bindingRedirect oldVersion="0.0.0.0-1.2.1.0" newVersion="1.2.1.0"/>
       </dependentAssembly>
     </assemblyBinding>
   </runtime>
-</configuration>
\ No newline at end of file
+  <startup>
+    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1"/>
+  </startup>
+</configuration>
diff --git a/ILSpy/ILSpy.csproj b/ILSpy/ILSpy.csproj
index ea199d97d..bed2058c2 100644
--- a/ILSpy/ILSpy.csproj
+++ b/ILSpy/ILSpy.csproj
@@ -7,7 +7,7 @@
     <OutputType>WinExe</OutputType>
     <RootNamespace>ICSharpCode.ILSpy</RootNamespace>
     <AssemblyName>ILSpy</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <TargetFrameworkProfile>
     </TargetFrameworkProfile>
diff --git a/TestPlugin/TestPlugin.csproj b/TestPlugin/TestPlugin.csproj
index 02f588056..cd77cf4dd 100644
--- a/TestPlugin/TestPlugin.csproj
+++ b/TestPlugin/TestPlugin.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
+<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" DefaultTargets="Build">
   <PropertyGroup>
     <ProjectGuid>{F32EBCC8-0E53-4421-867E-05B3D6E10C70}</ProjectGuid>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -7,7 +7,7 @@
     <OutputType>Library</OutputType>
     <RootNamespace>TestPlugin</RootNamespace>
     <AssemblyName>Test.Plugin</AssemblyName>
-    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <AllowUnsafeBlocks>False</AllowUnsafeBlocks>
     <NoStdLib>False</NoStdLib>