diff --git a/Before.Java.Interop.sln.targets b/Before.Java.Interop.sln.targets
index 09d57401a..6a0c00417 100644
--- a/Before.Java.Interop.sln.targets
+++ b/Before.Java.Interop.sln.targets
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <Import Project="$(MSBuildThisFileDirectory)build-tools\scripts\PrepareWindows.targets" Condition=" '$(OS)' == 'Windows_NT' " />
+  <Import Project="$(MSBuildThisFileDirectory)build-tools\scripts\Prepare.targets" />
   <Import Project="$(MSBuildThisFileDirectory)build-tools\scripts\RunNUnitTests.targets" />
 </Project>
\ No newline at end of file
diff --git a/Directory.Build.props b/Directory.Build.props
index 521e68a47..2d850d6a5 100644
--- a/Directory.Build.props
+++ b/Directory.Build.props
@@ -52,4 +52,11 @@
     <_XamarinAndroidCecilPath Condition=" '$(CecilSourceDirectory)' != '' And Exists('$(UtilityOutputFullPath)Xamarin.Android.Cecil.dll') ">$(UtilityOutputFullPath)Xamarin.Android.Cecil.dll</_XamarinAndroidCecilPath>
     <XamarinAndroidToolsFullPath>$([System.IO.Path]::GetFullPath ('$(XamarinAndroidToolsDirectory)'))</XamarinAndroidToolsFullPath>
   </PropertyGroup>
+  <PropertyGroup>
+    <Runtime Condition="'$(OS)' != 'Windows_NT'">mono</Runtime>
+    <_JNIEnvGenPath Condition=" '$(JIBuildingForNetCoreApp)' == 'True' ">$(BuildToolOutputFullPath)jnienv-gen.dll</_JNIEnvGenPath>
+    <_JNIEnvGenPath Condition=" '$(JIBuildingForNetCoreApp)' != 'True' ">$(BuildToolOutputFullPath)jnienv-gen.exe</_JNIEnvGenPath>
+    <_RunJNIEnvGen Condition=" '$(JIBuildingForNetCoreApp)' == 'True' ">dotnet "$(_JNIEnvGenPath)"</_RunJNIEnvGen>
+    <_RunJNIEnvGen Condition=" '$(JIBuildingForNetCoreApp)' != 'True' ">$(Runtime) "$(_JNIEnvGenPath)"</_RunJNIEnvGen>
+  </PropertyGroup>
 </Project>
diff --git a/Makefile b/Makefile
index dbadfd6f6..4c595a1b7 100644
--- a/Makefile
+++ b/Makefile
@@ -67,6 +67,8 @@ prepare-external $(PREPARE_EXTERNAL_FILES):
 	(cd external/xamarin-android-tools && $(MAKE) prepare)
 	nuget restore
 
+prepare-core: bin/Build$(CONFIGURATION)/MonoInfo.props src/Java.Runtime.Environment/Java.Runtime.Environment.dll.config
+
 clean:
 	-$(MSBUILD) $(MSBUILD_FLAGS) /t:Clean
 	-rm -Rf bin/$(CONFIGURATION) bin/Build$(CONFIGURATION) bin/Test$(CONFIGURATION)
diff --git a/build-tools/automation/azure-pipelines.yaml b/build-tools/automation/azure-pipelines.yaml
index c97e25fae..5f558b5fe 100644
--- a/build-tools/automation/azure-pipelines.yaml
+++ b/build-tools/automation/azure-pipelines.yaml
@@ -10,7 +10,7 @@ pr:
 
 # Global variables
 variables:
-  DotNetCoreVersion: 3.1.201
+  DotNetCoreVersion: 3.1.300
   HostedMac: Hosted Mac Internal
   HostedWinVS2019: Hosted Windows 2019 with VS2019
 
@@ -25,10 +25,7 @@ jobs:
   - checkout: self
     submodules: recursive
 
-  - task: UseDotNet@2
-    displayName: Use .NET Core $(DotNetCoreVersion)
-    inputs:
-      version: $(DotNetCoreVersion)
+  - template: templates\install-dependencies.yaml
 
   - task: NuGetToolInstaller@0
     inputs:
@@ -78,71 +75,13 @@ jobs:
   - checkout: self
     submodules: recursive
 
-  - task: UseDotNet@2
-    displayName: Use .NET Core $(DotNetCoreVersion)
-    inputs:
-      version: $(DotNetCoreVersion)
-
-  - task: DotNetCoreCLI@2
-    displayName: Prepare Solution
-    inputs:
-      projects: Java.Interop.sln
-      arguments: '-c $(Build.Configuration) -target:Prepare'
-
-  - task: DotNetCoreCLI@2
-    displayName: Build Solution
-    inputs:
-      projects: Java.Interop.sln
-      arguments: '-c $(Build.Configuration)'
-
-  - task: DotNetCoreCLI@2
-    displayName: 'Tests: Java.Interop.Tools.Generator'
-    inputs:
-      command: test
-      arguments: bin\Test$(Build.Configuration)\Java.Interop.Tools.Generator-Tests.dll
-    continueOnError: true
-
-  - task: DotNetCoreCLI@2
-    displayName: 'Tests: generator'
-    inputs:
-      command: test
-      arguments: bin\Test$(Build.Configuration)\generator-Tests.dll
-    continueOnError: true
-
-  - task: DotNetCoreCLI@2
-    displayName: 'Tests: JavaCallableWrappers'
-    inputs:
-      command: test
-      arguments: bin\Test$(Build.Configuration)\Java.Interop.Tools.JavaCallableWrappers-Tests.dll
-    continueOnError: true
+  - template: templates\install-dependencies.yaml
 
-  - task: DotNetCoreCLI@2
-    displayName: 'Tests: logcat-parse'
-    inputs:
-      command: test
-      arguments: bin\Test$(Build.Configuration)\logcat-parse-Tests.dll
-    continueOnError: true
+  - template: templates\core-build.yaml
 
-  - task: DotNetCoreCLI@2
-    displayName: 'Tests: ApiXmlAdjuster'
-    inputs:
-      command: test
-      arguments: bin\Test$(Build.Configuration)\Xamarin.Android.Tools.ApiXmlAdjuster-Tests.dll
-    continueOnError: true
+  - template: templates\core-tests.yaml
 
-  - task: DotNetCoreCLI@2
-    displayName: 'Tests: Bytecode'
-    inputs:
-      command: test
-      arguments: bin\Test$(Build.Configuration)\Xamarin.Android.Tools.Bytecode-Tests.dll
-    continueOnError: true
-
-  - powershell: |
-      Write-Host "Current job status is: $env:AGENT_JOBSTATUS"
-      if ($env:AGENT_JOBSTATUS -eq "SucceededWithIssues") {
-          Write-Host "##vso[task.complete result=Failed;]DONE"
-      }
-    displayName: Fail job if tests failed
+  - template: templates\fail-on-issue.yaml
     
 - job: mac_build
   displayName: Mac - Mono
@@ -154,15 +93,7 @@ jobs:
   - checkout: self
     submodules: recursive
 
-  - task: UseDotNet@2
-    displayName: Use .NET Core $(DotNetCoreVersion)
-    inputs:
-      version: $(DotNetCoreVersion)
-    
-  - script: |
-      dotnet tool install --global boots  
-      boots --stable Mono
-    displayName: Install Mono-Stable
+  - template: templates\install-dependencies.yaml
     
   - script: make prepare CONFIGURATION=$(Build.Configuration)
     displayName: make prepare
@@ -200,3 +131,24 @@ jobs:
     inputs:
       ArtifactName: debug
     condition: succeededOrFailed()
+    
+- job: mac_dotnet_build
+  displayName: Mac - .NET Core
+  pool: $(HostedMac)
+  timeoutInMinutes: 20
+  workspace:
+    clean: all
+  steps:
+  - checkout: self
+    submodules: recursive
+
+  - template: templates\install-dependencies.yaml
+    
+  - script: make prepare-core CONFIGURATION=$(Build.Configuration)
+    displayName: make prepare-core
+      
+  - template: templates\core-build.yaml
+      
+  - template: templates\core-tests.yaml
+
+  - template: templates\fail-on-issue.yaml
diff --git a/build-tools/automation/templates/core-build.yaml b/build-tools/automation/templates/core-build.yaml
new file mode 100644
index 000000000..b631aed7c
--- /dev/null
+++ b/build-tools/automation/templates/core-build.yaml
@@ -0,0 +1,15 @@
+parameters:
+  condition: succeeded()
+
+steps:
+- task: DotNetCoreCLI@2
+  displayName: Prepare Solution
+  inputs:
+    projects: Java.Interop.sln
+    arguments: '-c $(Build.Configuration) -target:Prepare'
+
+- task: DotNetCoreCLI@2
+  displayName: Build Solution
+  inputs:
+    projects: Java.Interop.sln
+    arguments: '-c $(Build.Configuration) -m:1'
diff --git a/build-tools/automation/templates/core-tests.yaml b/build-tools/automation/templates/core-tests.yaml
new file mode 100644
index 000000000..ba16127ac
--- /dev/null
+++ b/build-tools/automation/templates/core-tests.yaml
@@ -0,0 +1,74 @@
+parameters:
+  condition: succeeded()
+
+steps:
+- task: DotNetCoreCLI@2
+  displayName: 'Tests: generator'
+  inputs:
+    command: test
+    arguments: bin/Test$(Build.Configuration)/generator-Tests.dll
+  continueOnError: true
+  
+- task: DotNetCoreCLI@2
+  displayName: 'Tests: JavaCallableWrappers'
+  inputs:
+    command: test
+    arguments: bin/Test$(Build.Configuration)/Java.Interop.Tools.JavaCallableWrappers-Tests.dll
+  continueOnError: true
+   
+- task: DotNetCoreCLI@2
+  displayName: 'Tests: logcat-parse'
+  inputs:
+    command: test
+    arguments: bin/Test$(Build.Configuration)/logcat-parse-Tests.dll
+  continueOnError: true
+  
+- task: DotNetCoreCLI@2
+  displayName: 'Tests: ApiXmlAdjuster'
+  inputs:
+    command: test
+    arguments: bin/Test$(Build.Configuration)/Xamarin.Android.Tools.ApiXmlAdjuster-Tests.dll
+  continueOnError: true
+  
+- task: DotNetCoreCLI@2
+  displayName: 'Tests: Bytecode'
+  inputs:
+    command: test
+    arguments: bin/Test$(Build.Configuration)/Xamarin.Android.Tools.Bytecode-Tests.dll
+  continueOnError: true
+
+- task: DotNetCoreCLI@2
+  displayName: 'Tests: Java.Interop.Tools.Generator'
+  inputs:
+    command: test
+    arguments: bin/Test$(Build.Configuration)/Java.Interop.Tools.Generator-Tests.dll
+  continueOnError: true
+
+- task: DotNetCoreCLI@2
+  displayName: 'Tests: Java.Interop.Tools.JavaSource'
+  inputs:
+    command: test
+    arguments: bin/Test$(Build.Configuration)/Java.Interop.Tools.JavaSource-Tests.dll
+  continueOnError: true
+
+# Running native Java.Interop tests are not yet supported on .NET Core
+#- task: DotNetCoreCLI@2
+#  displayName: 'Tests: Java.Interop'
+#  inputs:
+#    command: test
+#    arguments: bin/Test$(Build.Configuration)/Java.Interop-Tests.dll
+#  continueOnError: true
+
+#- task: DotNetCoreCLI@2
+#  displayName: 'Tests: Java.Interop.Dynamic'
+#  inputs:
+#    command: test
+#    arguments: bin/Test$(Build.Configuration)/Java.Interop.Dynamic-Tests.dll
+#  continueOnError: true
+
+#- task: DotNetCoreCLI@2
+#  displayName: 'Tests: Java.Interop.Export'
+#  inputs:
+#    command: test
+#    arguments: bin/Test$(Build.Configuration)/Java.Interop.Export-Tests.dll
+#  continueOnError: true
diff --git a/build-tools/automation/templates/fail-on-issue.yaml b/build-tools/automation/templates/fail-on-issue.yaml
new file mode 100644
index 000000000..ad3f176f9
--- /dev/null
+++ b/build-tools/automation/templates/fail-on-issue.yaml
@@ -0,0 +1,10 @@
+parameters:
+  condition: succeeded()
+
+steps:
+- powershell: |
+    Write-Host "Current job status is: $env:AGENT_JOBSTATUS"
+    if ($env:AGENT_JOBSTATUS -eq "SucceededWithIssues") {
+        Write-Host "##vso[task.complete result=Failed;]DONE"
+    }
+  displayName: fail if any issues occurred
diff --git a/build-tools/automation/templates/install-dependencies.yaml b/build-tools/automation/templates/install-dependencies.yaml
new file mode 100644
index 000000000..8bd8bf2f4
--- /dev/null
+++ b/build-tools/automation/templates/install-dependencies.yaml
@@ -0,0 +1,14 @@
+parameters:
+  condition: succeeded()
+
+steps:
+- task: UseDotNet@2
+  displayName: Use .NET Core $(DotNetCoreVersion)
+  inputs:
+    version: $(DotNetCoreVersion)
+  
+- script: |
+    dotnet tool install --global boots  
+    boots --stable Mono
+  displayName: Install Mono-Stable
+  condition: and(succeeded(), eq(variables['agent.os'], 'Darwin'))
diff --git a/build-tools/jnienv-gen/jnienv-gen.csproj b/build-tools/jnienv-gen/jnienv-gen.csproj
index 94e11ce24..11caad93f 100644
--- a/build-tools/jnienv-gen/jnienv-gen.csproj
+++ b/build-tools/jnienv-gen/jnienv-gen.csproj
@@ -11,4 +11,7 @@
     <OutputPath>$(BuildToolOutputFullPath)</OutputPath>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
+  </ItemGroup>
 </Project>
diff --git a/build-tools/scripts/PrepareWindows.targets b/build-tools/scripts/Prepare.targets
similarity index 100%
rename from build-tools/scripts/PrepareWindows.targets
rename to build-tools/scripts/Prepare.targets
diff --git a/samples/Hello/Hello.csproj b/samples/Hello/Hello.csproj
index 4925324e2..402863d2a 100644
--- a/samples/Hello/Hello.csproj
+++ b/samples/Hello/Hello.csproj
@@ -11,6 +11,10 @@
     <OutputPath>$(TestOutputFullPath)</OutputPath>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
+  </ItemGroup>
+  
   <ItemGroup>
     <ProjectReference Include="..\..\src\Java.Interop\Java.Interop.csproj" />
     <ProjectReference Include="..\..\src\Java.Runtime.Environment\Java.Runtime.Environment.csproj" />
diff --git a/src/Java.Interop/Directory.Build.targets b/src/Java.Interop/Directory.Build.targets
index 205b49e0d..95609908a 100644
--- a/src/Java.Interop/Directory.Build.targets
+++ b/src/Java.Interop/Directory.Build.targets
@@ -1,12 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-  <PropertyGroup>
-    <Runtime Condition="'$(OS)' != 'Windows_NT'">mono</Runtime>
-    <_JNIEnvGenPath Condition=" '$(JIBuildingForNetCoreApp)' == 'True' ">$(BuildToolOutputFullPath)jnienv-gen.dll</_JNIEnvGenPath>
-    <_JNIEnvGenPath Condition=" '$(JIBuildingForNetCoreApp)' != 'True' ">$(BuildToolOutputFullPath)jnienv-gen.exe</_JNIEnvGenPath>
-    <_RunJNIEnvGen Condition=" '$(JIBuildingForNetCoreApp)' == 'True' ">dotnet "$(_JNIEnvGenPath)"</_RunJNIEnvGen>
-    <_RunJNIEnvGen Condition=" '$(JIBuildingForNetCoreApp)' != 'True' ">$(Runtime) "$(_JNIEnvGenPath)"</_RunJNIEnvGen>
-  </PropertyGroup>
   <ItemGroup>
     <CompileJavaInteropJar Include="java\com\xamarin\java_interop\internal\JavaProxyObject.java" />
     <CompileJavaInteropJar Include="java\com\xamarin\java_interop\internal\JavaProxyThrowable.java" />
@@ -21,16 +14,16 @@
   <Target Name="BuildJniEnvironment_g_cs"
       BeforeTargets="BeforeCompile"
       Inputs="$(_JNIEnvGenPath)"
-      Outputs="Java.Interop\JniEnvironment.g.cs;$(IntermediateOutputPath)\jni.c">
+      Outputs="Java.Interop/JniEnvironment.g.cs;$(IntermediateOutputPath)jni.c">
     <MakeDir Directories="$(IntermediateOutputPath)" />
     <PropertyGroup>
-      <_AddCompile Condition=" !Exists('Java.Interop\JniEnvironment.g.cs') ">True</_AddCompile>
+      <_AddCompile Condition=" !Exists('Java.Interop/JniEnvironment.g.cs') ">True</_AddCompile>
     </PropertyGroup>
     <Exec
-        Command="$(_RunJNIEnvGen) Java.Interop\JniEnvironment.g.cs $(IntermediateOutputPath)\jni.c"
+        Command="$(_RunJNIEnvGen) Java.Interop/JniEnvironment.g.cs $(IntermediateOutputPath)jni.c"
     />
     <ItemGroup>
-      <Compile Include="Java.Interop\JniEnvironment.g.cs" Condition=" '$(_AddCompile)' == 'True' " />
+      <Compile Include="Java.Interop/JniEnvironment.g.cs" Condition=" '$(_AddCompile)' == 'True' " />
     </ItemGroup>
   </Target>
   <Target Name="BuildInteropJar"
diff --git a/src/java-interop/java-interop.csproj b/src/java-interop/java-interop.csproj
index 079765dc6..404807066 100644
--- a/src/java-interop/java-interop.csproj
+++ b/src/java-interop/java-interop.csproj
@@ -44,7 +44,11 @@
   </ItemGroup>
 
   <Import Project="java-interop.targets" />
-  
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\..\build-tools\jnienv-gen\jnienv-gen.csproj" ReferenceOutputAssembly="false" />
   </ItemGroup>  
diff --git a/src/java-interop/java-interop.targets b/src/java-interop/java-interop.targets
index 7c8120ec7..87f5ec272 100644
--- a/src/java-interop/java-interop.targets
+++ b/src/java-interop/java-interop.targets
@@ -1,17 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
-  <PropertyGroup>
-    <Runtime Condition="'$(OS)' != 'Windows_NT'">mono</Runtime>
-  </PropertyGroup>
   <Target Name="BuildJni_c"
-      Inputs="$(JNIEnvGenPath)\jnienv-gen.exe"
+      Inputs="$(_JNIEnvGenPath)"
       Outputs="jni.c">
     <MakeDir Directories="$(OutputPath)" />
-    <Exec Command="$(Runtime) &quot;$(JNIEnvGenPath)\jnienv-gen.exe&quot; jni.g.cs jni.c" />
+    <Exec Command="$(_RunJNIEnvGen) jni.g.cs jni.c" />
   </Target>
 
   <PropertyGroup>
-    <_MacLib>$(OutputPath)\lib$(OutputName).dylib</_MacLib>
+    <_MacLib>$(OutputPath)/lib$(OutputName).dylib</_MacLib>
   </PropertyGroup>
 
   <Target Name="_CompileObjectFiles"
@@ -32,7 +29,7 @@
       <_Inc>@(_Includes->'-I "%(Identity)"', ' ')</_Inc>
     </PropertyGroup>
     <Exec
-        Command="$(_Cc) -c -g $(_Arch) -o &quot;obj\$(Configuration)\%(ClCompile.Filename).o&quot; $(_Def) $(_Inc) &quot;%(Identity)&quot;"
+        Command="$(_Cc) -c -g $(_Arch) -o &quot;obj/$(Configuration)/%(ClCompile.Filename).o&quot; $(_Def) $(_Inc) &quot;%(Identity)&quot;"
     />
   </Target>
 
@@ -47,7 +44,8 @@
       <_Libs>$(MonoLibs)</_Libs>
       <_Files>@(ClCompile->'obj\$(Configuration)\%(Filename).o', ' ')</_Files>
     </PropertyGroup>
-    <Exec Command="gcc -g -shared -m64 -std=c99 -fPIC -o &quot;$(_MacLib)&quot; $(_LinkFlags) $(_Libs) $(_Files)" />
+    <!-- Use 'IgnoreStandardErrorWarningFormat' to ignore 'ld: warning: text-based stub file X and and library file Y are out of sync' warnings. -->
+    <Exec Command="gcc -g -shared -m64 -std=c99 -fPIC -o &quot;$(_MacLib)&quot; $(_LinkFlags) $(_Libs) $(_Files)" IgnoreStandardErrorWarningFormat="true" />
     <!-- Mono 4.4.0 (mono-4.4.0-branch/a3fabf1) has an incorrect shared library name. Fix it -->
     <Exec Command="install_name_tool -change /private/tmp/source-mono-4.4.0/bockbuild-mono-4.4.0-branch/profiles/mono-mac-xamarin/package-root/lib/libmonosgen-2.0.1.dylib /Library/Frameworks/Mono.framework/Libraries/libmonosgen-2.0.1.dylib &quot;$(_MacLib)&quot;" />
   </Target>
@@ -69,7 +67,7 @@
       <_Libs>$(MonoLibs)</_Libs>
       <_Files>@(ClCompile->'obj\$(Configuration)\%(Filename).o', ' ')</_Files>
     </PropertyGroup>
-    <Exec Command="g++ -g -shared -o &quot;$(OutputPath)\lib$(OutputName).so&quot; $(_LinkFlags) $(_Libs) $(_Files)" />
+    <Exec Command="g++ -g -shared -o &quot;$(OutputPath)/lib$(OutputName).so&quot; $(_LinkFlags) $(_Libs) $(_Files)" />
   </Target>
 
   <Target Name="Clean">
diff --git a/tests/Java.Interop-PerformanceTests/Java.Interop-PerformanceTests.csproj b/tests/Java.Interop-PerformanceTests/Java.Interop-PerformanceTests.csproj
index b1eb84682..311f3e586 100644
--- a/tests/Java.Interop-PerformanceTests/Java.Interop-PerformanceTests.csproj
+++ b/tests/Java.Interop-PerformanceTests/Java.Interop-PerformanceTests.csproj
@@ -15,6 +15,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tests/Java.Interop-Tests/Java.Interop-Tests.csproj b/tests/Java.Interop-Tests/Java.Interop-Tests.csproj
index 7da6cb398..99adeff12 100644
--- a/tests/Java.Interop-Tests/Java.Interop-Tests.csproj
+++ b/tests/Java.Interop-Tests/Java.Interop-Tests.csproj
@@ -20,6 +20,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" GeneratePathProperty="true" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
@@ -42,7 +43,7 @@
 
   <Target Name="BuildInteropTestJar" BeforeTargets="BeforeBuild" Inputs="@(JavaInteropTestJar)" Outputs="$(OutputPath)interop-test.jar">
     <MakeDir Directories="$(IntermediateOutputPath)it-classes" />
-    <Exec Command="&quot;$(JavaCPath)&quot; $(_JavacSourceOptions) -d &quot;$(IntermediateOutputPath)it-classes&quot; -classpath &quot;$(OutputPath)..\$(Configuration)\java-interop.jar&quot; @(JavaInteropTestJar->'%(Identity)', ' ')" />
+    <Exec Command="&quot;$(JavaCPath)&quot; $(_JavacSourceOptions) -d &quot;$(IntermediateOutputPath)it-classes&quot; -classpath &quot;$(OutputPath)../$(Configuration)/java-interop.jar&quot; @(JavaInteropTestJar->'%(Identity)', ' ')" />
     <Exec Command="&quot;$(JarPath)&quot; cf &quot;$(OutputPath)interop-test.jar&quot; -C &quot;$(IntermediateOutputPath)it-classes&quot; ." />
   </Target>
 
diff --git a/tests/Java.Interop.Dynamic-Tests/Java.Interop.Dynamic-Tests.csproj b/tests/Java.Interop.Dynamic-Tests/Java.Interop.Dynamic-Tests.csproj
index 332940095..29eeb39ac 100644
--- a/tests/Java.Interop.Dynamic-Tests/Java.Interop.Dynamic-Tests.csproj
+++ b/tests/Java.Interop.Dynamic-Tests/Java.Interop.Dynamic-Tests.csproj
@@ -19,6 +19,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tests/Java.Interop.Export-Tests/Java.Interop.Export-Tests.csproj b/tests/Java.Interop.Export-Tests/Java.Interop.Export-Tests.csproj
index 635267802..a419f1b7f 100644
--- a/tests/Java.Interop.Export-Tests/Java.Interop.Export-Tests.csproj
+++ b/tests/Java.Interop.Export-Tests/Java.Interop.Export-Tests.csproj
@@ -16,6 +16,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
@@ -31,7 +32,7 @@
 
   <Target Name="BuildExportTestJar" BeforeTargets="BeforeBuild" Inputs="@(JavaExportTestJar)" Outputs="$(OutputPath)export-test.jar">
     <MakeDir Directories="$(IntermediateOutputPath)et-classes" />
-    <Exec Command="&quot;$(JavaCPath)&quot; -classpath &quot;$(OutputPath)..\$(Configuration)\java-interop.jar&quot; $(_JavacSourceOptions) -d &quot;$(IntermediateOutputPath)et-classes&quot; @(JavaExportTestJar->'%(Identity)', ' ')" />
+    <Exec Command="&quot;$(JavaCPath)&quot; -classpath &quot;$(OutputPath)../$(Configuration)/java-interop.jar&quot; $(_JavacSourceOptions) -d &quot;$(IntermediateOutputPath)et-classes&quot; @(JavaExportTestJar->'%(Identity)', ' ')" />
     <Exec Command="&quot;$(JarPath)&quot; cf &quot;$(OutputPath)export-test.jar&quot; -C &quot;$(IntermediateOutputPath)et-classes&quot; ." />
   </Target>
 
diff --git a/tests/Java.Interop.Tools.Generator-Tests/Java.Interop.Tools.Generator-Tests.csproj b/tests/Java.Interop.Tools.Generator-Tests/Java.Interop.Tools.Generator-Tests.csproj
index a556d2ff4..acea34c9d 100644
--- a/tests/Java.Interop.Tools.Generator-Tests/Java.Interop.Tools.Generator-Tests.csproj
+++ b/tests/Java.Interop.Tools.Generator-Tests/Java.Interop.Tools.Generator-Tests.csproj
@@ -15,6 +15,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers-Tests.csproj b/tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers-Tests.csproj
index f16ad4351..a2d6c88e4 100644
--- a/tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers-Tests.csproj
+++ b/tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers-Tests.csproj
@@ -17,6 +17,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tests/Java.Interop.Tools.JavaSource-Tests/Java.Interop.Tools.JavaSource-Tests.csproj b/tests/Java.Interop.Tools.JavaSource-Tests/Java.Interop.Tools.JavaSource-Tests.csproj
index 3ab2f12e3..fcba001d0 100644
--- a/tests/Java.Interop.Tools.JavaSource-Tests/Java.Interop.Tools.JavaSource-Tests.csproj
+++ b/tests/Java.Interop.Tools.JavaSource-Tests/Java.Interop.Tools.JavaSource-Tests.csproj
@@ -11,6 +11,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\src\Java.Interop.Tools.JavaSource\Java.Interop.Tools.JavaSource.csproj" />
diff --git a/tests/TestJVM/TestJVM.csproj b/tests/TestJVM/TestJVM.csproj
index 54965bae5..4d0d45a0f 100644
--- a/tests/TestJVM/TestJVM.csproj
+++ b/tests/TestJVM/TestJVM.csproj
@@ -14,6 +14,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tests/Xamarin.Android.Tools.ApiXmlAdjuster-Tests/Xamarin.Android.Tools.ApiXmlAdjuster-Tests.csproj b/tests/Xamarin.Android.Tools.ApiXmlAdjuster-Tests/Xamarin.Android.Tools.ApiXmlAdjuster-Tests.csproj
index 7d9cd12f4..bb5bcb475 100644
--- a/tests/Xamarin.Android.Tools.ApiXmlAdjuster-Tests/Xamarin.Android.Tools.ApiXmlAdjuster-Tests.csproj
+++ b/tests/Xamarin.Android.Tools.ApiXmlAdjuster-Tests/Xamarin.Android.Tools.ApiXmlAdjuster-Tests.csproj
@@ -14,6 +14,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tests/Xamarin.Android.Tools.Bytecode-Tests/Xamarin.Android.Tools.Bytecode-Tests.csproj b/tests/Xamarin.Android.Tools.Bytecode-Tests/Xamarin.Android.Tools.Bytecode-Tests.csproj
index 50a2a9a77..4be137c63 100644
--- a/tests/Xamarin.Android.Tools.Bytecode-Tests/Xamarin.Android.Tools.Bytecode-Tests.csproj
+++ b/tests/Xamarin.Android.Tools.Bytecode-Tests/Xamarin.Android.Tools.Bytecode-Tests.csproj
@@ -14,6 +14,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
@@ -52,7 +53,7 @@
 
   <Target Name="BuildClasses" BeforeTargets="BeforeBuild" Inputs="@(TestJar)" Outputs="@(TestJar->'$(IntermediateOutputPath)classes\%(RecursiveDir)%(Filename).class')">
     <MakeDir Directories="$(IntermediateOutputPath)classes" />
-    <Exec Command="&quot;$(JavaCPath)&quot; -parameters $(_JavacSourceOptions) -g -d &quot;$(IntermediateOutputPath)classes&quot; java\android\annotation\NonNull.java @(TestJar->'%(Identity)', ' ')" />
+    <Exec Command="&quot;$(JavaCPath)&quot; -parameters $(_JavacSourceOptions) -g -d &quot;$(IntermediateOutputPath)classes&quot; java/android/annotation/NonNull.java @(TestJar->'%(Identity)', ' ')" />
     <Exec Command="&quot;$(JavaCPath)&quot; $(_JavacSourceOptions) -g -d &quot;$(IntermediateOutputPath)classes&quot; @(TestJarNoParameters->'%(Identity)', ' ')" />
   </Target>
 
diff --git a/tests/generator-Tests/generator-Tests.csproj b/tests/generator-Tests/generator-Tests.csproj
index 28930d381..676b24374 100644
--- a/tests/generator-Tests/generator-Tests.csproj
+++ b/tests/generator-Tests/generator-Tests.csproj
@@ -18,6 +18,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tests/logcat-parse-Tests/logcat-parse-Tests.csproj b/tests/logcat-parse-Tests/logcat-parse-Tests.csproj
index 427208207..9414d13b3 100644
--- a/tests/logcat-parse-Tests/logcat-parse-Tests.csproj
+++ b/tests/logcat-parse-Tests/logcat-parse-Tests.csproj
@@ -14,6 +14,7 @@
     <PackageReference Include="NUnit.ConsoleRunner" Version="3.9.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.13.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tools/class-parse/class-parse.csproj b/tools/class-parse/class-parse.csproj
index da6a86a52..43f43f3de 100644
--- a/tools/class-parse/class-parse.csproj
+++ b/tools/class-parse/class-parse.csproj
@@ -11,6 +11,7 @@
 
   <ItemGroup>
     <PackageReference Include="Mono.Options" Version="5.3.0.1" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tools/generator/generator.csproj b/tools/generator/generator.csproj
index e95c7c7d0..86e0fc58f 100644
--- a/tools/generator/generator.csproj
+++ b/tools/generator/generator.csproj
@@ -37,6 +37,7 @@
     <Reference Include="HtmlAgilityPack">
         <HintPath>$(PkgHtmlAgilityPack)\lib\netstandard2.0\HtmlAgilityPack.dll</HintPath>
     </Reference>
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tools/jcw-gen/jcw-gen.csproj b/tools/jcw-gen/jcw-gen.csproj
index fce17425b..16ae9a47e 100644
--- a/tools/jcw-gen/jcw-gen.csproj
+++ b/tools/jcw-gen/jcw-gen.csproj
@@ -11,6 +11,7 @@
 
   <ItemGroup>
     <PackageReference Include="Mono.Options" Version="5.3.0.1" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <Import Project="..\..\build-tools\scripts\cecil.projitems" />
diff --git a/tools/jnimarshalmethod-gen/Xamarin.Android.Tools.JniMarshalMethodGenerator.csproj b/tools/jnimarshalmethod-gen/Xamarin.Android.Tools.JniMarshalMethodGenerator.csproj
index 97ffb58df..ac7dcab72 100644
--- a/tools/jnimarshalmethod-gen/Xamarin.Android.Tools.JniMarshalMethodGenerator.csproj
+++ b/tools/jnimarshalmethod-gen/Xamarin.Android.Tools.JniMarshalMethodGenerator.csproj
@@ -23,6 +23,7 @@
     
   <ItemGroup>
     <PackageReference Include="Mono.Options" Version="5.3.0.1" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(_DumpRegisterNativeMembers)' == 'True' ">
diff --git a/tools/logcat-parse/logcat-parse.csproj b/tools/logcat-parse/logcat-parse.csproj
index 417f25d93..5fd738989 100644
--- a/tools/logcat-parse/logcat-parse.csproj
+++ b/tools/logcat-parse/logcat-parse.csproj
@@ -13,6 +13,7 @@
     <PackageReference Include="Mono.Options" Version="5.3.0.1" />
     <PackageReference Include="Mono.Terminal" Version="5.4.0" />
     <PackageReference Include="Mono.CSharp" Version="4.0.0.143" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/tools/param-name-importer/param-name-importer.csproj b/tools/param-name-importer/param-name-importer.csproj
index 1c2e0ee38..e2105d242 100644
--- a/tools/param-name-importer/param-name-importer.csproj
+++ b/tools/param-name-importer/param-name-importer.csproj
@@ -20,6 +20,7 @@
       <HintPath>$(PkgMicrosoft_Xml_SgmlReader)\lib\netstandard2.0\SgmlReaderDll.dll</HintPath>
     </Reference>
     <PackageReference Include="Mono.Options" Version="5.3.0.1" />
+    <PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" PrivateAssets="All" Version="1.0.0" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\src\Java.Interop.Tools.JavaSource\Java.Interop.Tools.JavaSource.csproj" />